Dr Paul Kinsler.
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<> To: eenpk%bloch.leeds.ac.uk@bids.ac.uk
<> Subject: BIDS-cite-mori_n(1 slash 2)
<> X-VMS-To: eenpk@bloch.leeds.ac.uk
<> Status: O
<>
<> Copyright 1997, Institute for Scientific Information Inc.
<>
<> Database: Science Citation Index
<>
<> (1) TI: VARIATION IN FREQUENCIES OF CONFINED LONGITUDINAL-OPTICAL
<> PHONON MODES DUE TO CHANGES IN THE EFFECTIVE FORCE-CONSTANTS
<> NEAR HETEROJUNCTION INTERFACES
<> AU: STROSCIO_MA, KIM_KW, HALL_JC
<> NA: USA,RES OFF,RES TRIANGLE PK,NC,27709
<> N CAROLINA STATE UNIV,DEPT ELECT & COMP ENGN,RALEIGH,NC,27695
<> JN: SUPERLATTICES AND MICROSTRUCTURES, 1990, Vol.7, No.2, pp.115-
<> 118
<>
<> (2) TI: DYNAMIC SCREENING OF A POLAR OPTICAL PHONON BOUND TO A QUANTUM-
<> WELL - LOCALIZED PHONON MAGNETOPLASMON MODES
<> AU: GUREVICH_VL, SHTENGEL_KE
<> NA: AF IOFFE INST,LENINGRAD 194021,USSR
<> JN: JOURNAL OF PHYSICS-CONDENSED MATTER, 1990, Vol.2, No.29,
<> pp.6323-6326
<> DT: Letter
<>
<> (3) TI: POLARIZATION EIGENVECTORS OF SURFACE-OPTICAL PHONON MODES IN A
<> RECTANGULAR QUANTUM WIRE
<> AU: STROSCIO_MA, KIM_KW, LITTLEJOHN_MA, CHUANG_HH
<> NA: USA,RES OFF,POB 12211,RES TRIANGLE PK,NC,27709
<> N CAROLINA STATE UNIV,DEPT ELECT & COMP ENGN,RALEIGH,NC,27695
<> DUKE UNIV,DEPT ELECT ENGN,DURHAM,NC,27706
<> JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1990, Vol.42, No.2,
<> pp.1488-1491
<> DT: Note
<>
<> (4) TI: SIZE DEPENDENCE OF ELECTRON-PHONON COUPLING IN SEMICONDUCTOR
<> NANOSPHERES - THE CASE OF CDSE
<> AU: KLEIN_MC, HACHE_F, RICARD_D, FLYTZANIS_C
<> NA: ECOLE POLYTECH,CNRS,OPT QUANT LAB,F-91128 PALAISEAU,FRANCE
<> JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1990, Vol.42, No.17,
<> pp.11123-11132
<>
<> (5) TI: RESONANT POLARON EFFECT IN QUANTUM-WELLS
<> AU: HU_CD, CHANG_YH
<> NA: NATL TAIWAN UNIV,DEPT PHYS,TAIPEI 10764,TAIWAN
<> JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1990, Vol.42, No.17,
<> pp.11086-11092
<>
<> (6) TI: POLARON ENERGY AND EFFECTIVE MASS IN A QUANTUM-WELL
<> AU: HAI_GQ, PEETERS_FM, DEVREESE_JT
<> NA: UNIV INSTELLING ANTWERP,DEPT PHYS,UNIVERSITEITSPLEIN 1,B-2610
<> WILRIJK,BELGIUM
<> JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1990, Vol.42, No.17,
<> pp.11063-11072
<>
<> (7) TI: ELECTRON-OPTICAL-PHONON INTERACTION IN BINARY TERNARY
<> HETEROSTRUCTURES
<> AU: KIM_KW, STROSCIO_MA
<> NA: N CAROLINA STATE UNIV,DEPT ELECT & COMP ENGN,RALEIGH,NC,27695
<> USA,RES OFF,RES TRIANGLE PK,NC,27709
<> JN: JOURNAL OF APPLIED PHYSICS, 1990, Vol.68, No.12, pp.6289-6293
<> AB: The macroscopic dielectric continuum model is used to derive
<> electron-optical-phonon interaction Hamiltonians for
<> binary/ternary heterostructures containing both single and
<> double heterointerfaces. The formulation presented in this work
<> leads to a general prescription for the calculation of mode-
<> strength coefficients in ternary-containing heterostructures.
<> An illustration of these results is provided by exhibiting the
<> mode strengths of the interaction Hamiltonians for the
<> interface and the half-space longitudinal optical modes in a
<> GaAs/Al(y)Ga(1-y)As single heterostructure.
<> KP: SCATTERING, POLARIZABILITY, SEMICONDUCTOR, SLAB
<>
<> (8) TI: TRANSIENT SIMULATION OF ELECTRON-EMISSION FROM QUANTUM-WIRE
<> STRUCTURES
<> AU: BRIGGS_S, LEBURTON_JP
<> NA: UNIV ILLINOIS,BECKMAN INST ADV SCI & TECHNOL,DEPT ELECT & COMP
<> ENGN,URBANA,IL,61801
<> JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1991, Vol.43, No.6,
<> pp.4785-4791
<> AB: We model a GaAs quasi-one-dimensional quantum wire in an
<> applied longitudinal field and focus on mechanisms of electron
<> emission leading to real-space transfer from the wire. The
<> Monte Carlo simulation assumes an initial electron distribution
<> in the wire and calculates the time required for electrons to
<> undergo nonequivalent intervalley scattering to three-
<> dimensional states. The model includes multiple subbands, polar
<> optic and acoustic phonons, intervalley scattering, and band-
<> structure nonparabolicity. Results have been obtained for
<> different confinement conditions as well as different
<> temperatures. We find that the required time is a very strong
<> function of the longitudinal field and ranges from 4 ns down to
<> 1 ps for fields in the range of 100 V/cm to 8 kV/cm. The
<> corresponding distances in the wire vary from 130-mu-m down to
<> the submicrometer range.
<> KP: TRANSPORT-PROPERTIES, INVERSION LINES, SEMICONDUCTORS,
<> SCATTERING, MOBILITY, HETEROSTRUCTURES
<>
<> (9) TI: HOT-ELECTRONS IN LOW-DIMENSIONAL STRUCTURES
<> AU: RIDLEY_BK
<> NA: UNIV ESSEX,DEPT PHYS,WIVENHOE PK,COLCHESTER CO4
<> 3SQ,ESSEX,ENGLAND
<> JN: REPORTS ON PROGRESS IN PHYSICS, 1991, Vol.54, No.2, pp.169-256
<> DT: Review
<> AB: The properties of hot electrons in systems where electrons and
<> phonons experience quantum confinement are reviewed. The
<> modifications to the behaviour of electrons and phonons brought
<> about by confinement are described, particularly with reference
<> to the principal scattering mechanisms. The latter include the
<> interaction with longitudinal optical phonons and plasmons,
<> along with carrier-carrier effects. Some conflict in the
<> literature concerning Fuchs-Kliewer polaritons is discussed.
<> Low-temperature interactions with acoustic phonons are
<> described. A central topic is that of energy relaxation, and
<> the experimental and theoretical data relating to this form a
<> large part of the review. Energy relaxation mechanisms in the
<> femtosecond to nanosecond regimes, including intersubband and
<> well-capture processes, are eventually summarized. An equally
<> large section deals with hot-electron transport; in which
<> negative differential resistance and other instabilities
<> associated with parallel transport are discussed before turning
<> to ballistic transport and impact ionization.
<> KP: QUANTUM-WELL STRUCTURES, GAAS-ALGAAS HETEROSTRUCTURES, OPTICAL-
<> PHONON INTERACTION, REAL-SPACE TRANSFER, MODULATION-DOPED
<> HETEROSTRUCTURES, NEGATIVE DIFFERENTIAL RESISTANCE, ENVELOPE-
<> FUNCTION APPROXIMATION, IMPACT IONIZATION COEFFICIENTS, HIGHLY
<> EXCITED CARRIERS, ENERGY RELAXATION RATES
<>
<> (10) TI: DIFFERENCE PHONON-SCATTERING - A RAMAN EXCITATION IN GAAS
<> QUANTUM-WELLS
<> AU: LIU_Y, SOORYAKUMAR_R, KOTELES_ES, ELMAN_B
<> NA: OHIO STATE UNIV,DEPT PHYS,COLUMBUS,OH,43210
<> GTE LABS INC,WALTHAM,MA,02254
<> JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1991, Vol.43, No.8,
<> pp.6832-6835
<> DT: Note
<> AB: We report on a triply resonant fourth-order Raman excitation in
<> single GaAs quantum wells as narrow as 7 monolayers. The
<> scattering, observed at about 3 meV, is a direct manifestation
<> of extreme resonant inter-valence-subband coupling of confined
<> TO and LO phonons. The peak is associated with difference
<> scattering of these optical phonons via deformation-potential-
<> mediated electron-phonon coupling in the laminar structure.
<> Uniaxial stress provides an excellent means to modify the hole
<> states and thus directly control the Raman activity of this
<> excitation.
<> KP: GE
<>
<> (11) TI: INTERFACE-PHONON-MEDIATED MAGNETOPOLARONIC EFFECT ON IMPURITY
<> TRANSITION ENERGIES IN QUANTUM-WELLS
<> AU: LIN_DL, CHEN_R, GEORGE_TF
<> NA: SUNY BUFFALO,DEPT PHYS & ASTRON,BUFFALO,NY,14260
<> JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1991, Vol.43, No.11,
<> pp.9328-9331
<> DT: Note
<> AB: Electron interactions with interface phonon modes and strictly
<> confined bulk phonon modes are considered to calculate the
<> resonant magnetopolaronic 1s-2p+ transition energy of a
<> hydrogenic impurity in the quantum well of a double
<> heterostructure. An interaction gap is predicted between the
<> bulk LO and TO frequencies, in contrast to the Frohlich-type
<> interaction. These results are in good agreement with recent
<> experimental data.
<> KP: GAAS-ALAS SUPERLATTICES, DOUBLE HETEROSTRUCTURES, FROHLICH
<> INTERACTION, ELECTRON
<>
<> (12) TI: EFFECTS OF QUANTUM-MECHANICAL CORRECTIONS TO IMAGE POTENTIALS
<> ON THE BINDING-ENERGIES OF SURFACE POLARONS OUTSIDE POLAR
<> CRYSTALS
<> AU: SUN_H, GU_SW
<> NA: CHINESE CTR ADV SCI & TECHNOL,WORLD LAB,BEIJING 100080,PEOPLES
<> R CHINA
<> JIAO TONG UNIV,INST CONDENSED MATTER PHYS,SHANGHAI
<> 200030,PEOPLES R CHINA
<> JIAO TONG UNIV,DEPT PHYS,SHANGHAI 200030,PEOPLES R CHINA
<> ACAD SINICA,INT CTR MAT PHYS,SHENYANG 110015,PEOPLES R CHINA
<> JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1991, Vol.44, No.3,
<> pp.1163-1167
<> AB: Binding energies of surface polarons outside polar-crystal
<> surfaces are calculated by considering interactions of
<> electrons outside with both electronic and ionic polarizations
<> of crystals quantum mechanically. Our results show that
<> quantum-mechanical modifications of image potentials due to
<> electronic polarizations reduce polaron binding energies by 40-
<> 55% compared to those calculated with image potentials due to
<> electronic polarization approximated by their electrostatic
<> limits; substitution of infinitely high frequencies for the
<> finite vibrational frequencies of electronic polarizations,
<> however, changes the calculated polaron binding energies by
<> less than 10% for the wide-band materials considered.
<> KP: ELECTRON-PHONON INTERACTION, MODEL, POLARIZABILITY
<>
<> (13) TI: ELECTRON-OPTICAL-PHONON SCATTERING RATES IN A RECTANGULAR
<> SEMICONDUCTOR QUANTUM WIRE
<> AU: KIM_KW, STROSCIO_MA, BHATT_A, MICKEVICIUS_R, MITIN_VV
<> NA: N CAROLINA STATE UNIV,DEPT ELECT & COMP ENGN,RALEIGH,NC,27695
<> USA,RES OFF,RES TRIANGLE PK,NC,27709
<> WAYNE STATE UNIV,DEPT ELECT & COMP ENGN,DETROIT,MI,48202
<> JN: JOURNAL OF APPLIED PHYSICS, 1991, Vol.70, No.1, pp.319-325
<> AB: One-dimensional electron-optical-phonon interaction
<> Hamiltonians in a rectangular quantum wire consisting of
<> diatomic polar semiconductors are derived under the macroscopic
<> dielectric continuum model. The scattering rates calculated in
<> a GaAs square quantum wire show that when the quantum wire is
<> free-standing in vacuum, the interaction by the surface-optical
<> phonon modes is very strong and may dominate over other
<> scattering processes, especially with dimensions of about 100
<> angstrom or less. When the wire is embeded in a polar
<> semiconductor (AlAs to be specific), the scattering rates by
<> the confined longitudinal-optical modes as the wire dimension
<> shrinks. A considerable decrease in the total scattering rate
<> for optical phonons as a result of simple reduction in
<> dimensionality is not observed in this study.
<> KP: CONFINED LO, MODES, POLARIZABILITY, SUPERLATTICES, GAS
<>
<> (14) TI: POLARON GROUND-STATE IN A DOUBLE HETEROSTRUCTURE OF POLAR
<> CRYSTALS
<> AU: LIN_DL, CHEN_R, GEORGE_TF
<> NA: SUNY BUFFALO,DEPT PHYS & ASTRON,BUFFALO,NY,14260
<> JN: JOURNAL OF PHYSICS-CONDENSED MATTER, 1991, Vol.3, No.25,
<> pp.4645-4653
<> AB: The ground-state energy and effective mass of a polaron in the
<> GaAs well of a GaAs/AlAs double heterostructure are calculated
<> as functions of the well width. In considering electron-phonon
<> interactions, we have included both the confined longitudinal
<> optical (LO) as well as the interface phonon modes. The results
<> differ qualitatively from what can be found in the literature,
<> demonstrating the importance of interface modes as well as the
<> confinement of LO modes.
<> KP: OPTICAL-PHONON INTERACTION, GAAS-ALAS SUPERLATTICES, QUANTUM-
<> WELL STRUCTURES, INTERFACE PHONONS, MODES, LO
<>
<> (15) TI: BOUNDARY-CONDITIONS FOR ELECTRON-LO-PHONON INTERACTION IN POLAR
<> SEMICONDUCTOR QUANTUM WIRES
<> AU: STROSCIO_MA, KIM_KW, RUDIN_S
<> NA: USA,RES OFF,RES TRIANGLE PK,NC,27709
<> N CAROLINA STATE UNIV,DEPT ELECT & COMP ENGN,RALEIGH,NC,27695
<> USA,ELECTR TECHNOL & DEVICES LAB,FT MONMOUTH,NJ,07703
<> JN: SUPERLATTICES AND MICROSTRUCTURES, 1991, Vol.10, No.1, pp.55-58
<> KP: SUPERLATTICES, SCATTERING, MODES
<>
<> (16) TI: ELECTRON-PHONON INTERACTION AND ELECTRON-SCATTERING BY MODIFIED
<> CONFINED LO PHONONS IN SEMICONDUCTOR QUANTUM-WELLS
<> AU: HAUPT_R, WENDLER_L
<> NA: UNIV JENA,FAK PHYS ASTRON,MAX WIEN PL 1,O-6900 JENA,GERMANY
<> TECH UNIV MERSEBURG,FACHBEREICH PHYS,W-4200 MERSEBURG,GERMANY
<> JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1991, Vol.44, No.4,
<> pp.1850-1860
<> AB: An improved model of electron-phonon interaction for
<> longitudinal-optical phonons in layered semiconductor quantum
<> wells is developed. In this simple modified dielectric
<> continuum model, the LO phonons are confined modes having
<> electric and displacement fields that agree with both
<> electrostatics and microscopic models of longitudinal-optical
<> phonons. Numerical results are presented and discussed for the
<> electric fields of these modes. The resulting scattering rates
<> of electrons for emission and absorption of LO phonons in a
<> quantum well are calculated and presented in graphical form.
<> KP: POLAR-OPTICAL PHONONS, GAAS-ALAS SUPERLATTICES, DOUBLE
<> HETEROSTRUCTURES, QUASI-2-DIMENSIONAL SEMICONDUCTOR, GAAS/ALAS
<> SUPERLATTICES, FROHLICH INTERACTION, RAMAN-SCATTERING, MODES,
<> POLARIZABILITY, EXCITATIONS
<>
<> (17) TI: CONSTRAINTS ON THE POLAR-OPTICAL-PHONON INFLUENCE FUNCTIONAL IN
<> HETEROSTRUCTURES
<> AU: REGISTER_LF, STROSCIO_MA, LITTLEJOHN_MA
<> NA: N CAROLINA STATE UNIV,DEPT ELECT & COMP ENGN,RALEIGH,NC,27695
<> UNIV ILLINOIS,BECKMAN INST,URBANA,IL,61801
<> UNIV ILLINOIS,COORDINATED SCI LAB,URBANA,IL,61801
<> USA,RES OFF,RES TRIANGLE PK,NC,27709
<> JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1991, Vol.44, No.8,
<> pp.3850-3853
<> AB: The Feynman influence functional for the polar coupling of
<> carriers to confined phonon modes in heterostructures is
<> considered. It is found that the partial contributions to the
<> total influence functional from the individual branches of the
<> optical-phonon energy spectrum are related and constrained by
<> conservation relations. The derivation of these conservation
<> relations requires no specific functional form for the phonon
<> modes; rather it employs only the inherent orthogonality and
<> mathematical completeness of the classical vibrational modes
<> over the crystal-lattice degrees of freedom. In the bulk-
<> crystal limit these conservation relations lead to the familiar
<> results of Feynman; for arbitrary heterostructures, these
<> conservation relations provide a basis for an estimation of the
<> influence functional from limited knowledge of the spatial
<> confinement of the individual phonon branches.
<> KP: DEVICE APPLICATIONS, MODES, WIRE
<>
<> (18) TI: TRANSITION FROM LONGITUDINAL-OPTICAL PHONON-SCATTERING TO
<> SURFACE-OPTICAL PHONON-SCATTERING IN POLAR SEMICONDUCTOR
<> SUPERLATTICES
<> AU: STROSCIO_MA, IAFRATE_GJ, KIM_KW, LITTLEJOHN_MA, GORONKIN_H,
<> MARACAS_GN
<> NA: USA,RES OFF,RES TRIANGLE PK,NC,27709
<> N CAROLINA STATE UNIV,DEPT ELECT & COMP ENGN,RALEIGH,NC,27695
<> MOTOROLA PHOENIX CORP,RES LAB,TEMPE,AZ,85284
<> ARIZONA STATE UNIV,DEPT ELECT ENGN,TEMPE,AZ,85281
<> JN: APPLIED PHYSICS LETTERS, 1991, Vol.59, No.9, pp.1093-1095
<> AB: Dielectric continuum models of optical-phonon modes predict an
<> enhancement in the strength of the surface-optical (SO) modes
<> in double-barrier heterostructures as the heterojunction-to-
<> heterojunction separation is reduced. There is currently no
<> consensus on the nature of the electron-SO-phonon coupling
<> interaction. In this work, the ratio of electron scattering by
<> the SO-phonon modes to that by the confined longitudinal-
<> optical (LO) phonon modes is calculated for a GaAs/AlAs short-
<> period superlattice based on the assumption that the electron-
<> SO-phonon interaction may be described by a scalar potential.
<> The scaling of the ratio of electron-SO-phonon scattering to
<> electron-LO-phonon scattering as a function of the superlattice
<> period provides a sensitive test of the appropriateness of the
<> scalar-potential model.
<> KP: RECTANGULAR QUANTUM WIRE, ELECTRONIC POLARIZABILITY, DOUBLE
<> HETEROSTRUCTURES, FROHLICH INTERACTION, MODES
<>
<> (19) TI: ELECTRON-PHONON INTERACTION IN QUASI-2-DIMENSIONAL SYSTEMS
<> AU: RUCKER_H, MOLINARI_E, LUGLI_P
<> NA: HUMBOLDT UNIV,FACHBEREICH PHYS,INVALIDENSTR 110,O-1086
<> BERLIN,GERMANY
<> CNR,IST ACUST OM CORBINO,I-00189 ROME,ITALY
<> UNIV ROME,DIPARTIMENTO INGN MECCAN,I-00173 ROME,ITALY
<> JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1991, Vol.44, No.7,
<> pp.3463-3466
<> DT: Note
<> AB: We present a calculation of the electron-LO-phonon scattering
<> rate in quasi-two-dimensional systems, based on a fully
<> microscopic description of the phonon spectra. The results
<> obtained for a GaAs/AlAs quantum-well structure indicate the
<> great importance of interface phonons and allow us to solve a
<> long-standing controversy on the validity of simplified
<> macroscopic models for describing the relevant vibrations.
<> KP: SEMICONDUCTOR QUANTUM-WELLS, GAAS-ALAS SUPERLATTICES, GAAS/ALAS
<> SUPERLATTICES, DOUBLE HETEROSTRUCTURES, OPTICAL PHONONS,
<> INTERFACE MODES, CONFINED LO, SCATTERING, DYNAMICS, SPECTRA
<>
<> (20) TI: ELECTRONIC WAVE-FUNCTIONS AND ELECTRON-CONFINED-PHONON MATRIX-
<> ELEMENTS IN GAAS/ALXGA1-XAS DOUBLE-BARRIER RESONANT-TUNNELING
<> STRUCTURES
<> AU: TURLEY_PJ, TEITSWORTH_SW
<> NA: DUKE UNIV,DEPT PHYS,DURHAM,NC,27706
<> JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1991, Vol.44, No.7,
<> pp.3199-3210
<> AB: We have numerically studied spatial properties of electronic
<> wave functions in GaAs/Al(x)Ga(1-x)As double-barrier resonant-
<> tunneling (DBRT) structures, particularly those properties
<> which strongly affect the interaction of electrons with
<> confined phonon modes in the barrier and quantum-well layers
<> and play a role in phonon-assisted tunneling. We use a
<> transfer-matrix approach to examine the detailed spatial
<> structure of DBRT electronic wave functions for various
<> injection energies and applied voltages in two representative
<> structures. In addition to verifying expected behavior for
<> transmission probability and scattering phase shift versus
<> energy, we find that, off resonance, the electronic wave
<> functions show significant spatial asymmetry in the well layer,
<> which enhances coupling of electrons to shorter-wavelength
<> confined phonon modes. A formula for the excess current due to
<> phonon-assisted tunneling is given. Finally, we present
<> numerical evaluations of the matrix elements which describe the
<> electron-confined-LO-phonon interaction for lower-order
<> confined modes and these indicate that phonon emission occurs
<> preferentially in the GaAs well and not the Al(x)Ga(1-x)As
<> barrier layers for typical DBRT structures.
<> KP: QUANTUM-WELL, ELASTIC-SCATTERING, HETEROSTRUCTURES, EMISSION,
<> FIELD, SUPERLATTICES, SYSTEMS, DEVICES, SINGLE, STATES
<>
<> (21) TI: MODEL FOR LONGITUDINAL-OPTICAL PHONONS AND ELECTRON-PHONON
<> COUPLING IN GAAS-GA1-XALXAS MULTILAYER STRUCTURES
<> AU: GUILLEMOT_C, CLEROT_F
<> NA: CTR NATL ETUD TELECOMMUN,F-22301 LANNION,FRANCE
<> JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1991, Vol.44, No.12,
<> pp.6249-6261
<> AB: A continuum theory is developed to investigate the properties
<> of the long-wavelength longitudinal-optical phonons in GaAs-
<> Ga1-xAlxAs multilayer structures and the associated electron-
<> phonon interaction. Depending on the layer, the relative ionic
<> displacements are related to GaAs or GaAs-type longitudinal-
<> optical phonons and treated in the framework of the Born-Huang
<> model, generalized to include isotropic dispersion effects in
<> the Brillouin-zone center. For double heterostructures, a
<> finite number of quantized confined modes is found. The
<> interplay between the long-range Coulomb interaction, which
<> couples the vibrations of adjacent GaAs layers, and confinement
<> effects, which prevent the displacements of adjacent GaAs
<> layers to overlap, is elucidated in the case of superlattices.
<> The strength of the electron-phonon coupling in double
<> heterostructures is reduced as compared with the electron-bulk-
<> phonon effective coupling strength for quantum-well widths
<> smaller than 100 angstrom.
<> KP: GAAS-ALAS SUPERLATTICES, RESONANCE RAMAN-SCATTERING, QUANTUM-
<> WELLS, CONFINED LO, GAAS/ALAS SUPERLATTICES, VIBRATIONAL-MODES,
<> INTERFACE MODES, HETEROSTRUCTURES, ANISOTROPY, RELAXATION
<>
<> (22) TI: ELECTRONIC STATES IN SEMICONDUCTOR HETEROSTRUCTURES
<> AU: BASTARD_G, BRUM_JA, FERREIRA_R
<> NA: ECOLE NORM SUPER,DEPT PHYS,24 RUE LHMOND,F-75231 PARIS
<> 05,FRANCE
<> UNIV ESTADUAL CAMPINAS,DEPT FIS,BR-13081 SAO PAULO,BRAZIL
<> JN: SOLID STATE PHYSICS-ADVANCES IN RESEARCH AND APPLICATIONS,
<> 1991, Vol.44, pp.229-415
<> DT: Review
<> KP: QUANTUM-WELL STRUCTURES, GAAS-ALAS SUPERLATTICES, EXCITON
<> BINDING-ENERGY, ENVELOPE-FUNCTION APPROXIMATION, INTERFACE
<> ROUGHNESS SCATTERING, VALENCE-BAND DISCONTINUITY, SHORT-PERIOD
<> SUPERLATTICES, LOW-TEMPERATURE MOBILITY, HGTE-CDTE
<> SUPERLATTICES, EFFECTIVE-MASS EQUATION
<>
<> (23) TI: ELECTRON-OPTICAL-PHONON INTERACTIONS IN ULTRATHIN GAAS/ALAS
<> MULTIPLE QUANTUM-WELLS
<> AU: TSEN_KT, WALD_KR, RUF_T, YU_PY, MORKOC_H
<> NA: ARIZONA STATE UNIV,DEPT PHYS,TEMPE,AZ,85287
<> UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA,94720
<> UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DIV MAT
<> SCI,BERKELEY,CA,94720
<> UNIV ILLINOIS,COORDINATED SCI LAB,URBANA,IL,61801
<> JN: PHYSICAL REVIEW LETTERS, 1991, Vol.67, No.18, pp.2557-2560
<> AB: Nonequilibrium populations of both confined and interface
<> phonons generated by picosecond laser pulses in a series of
<> GaAs/AlAs quantum wells have been studied by time-resolved
<> picosecond Raman scattering as a function of well width. The
<> dependence of the nonequilibrium phonon populations on well
<> width is found to be sensitive to the theoretical model which
<> is used to describe the electron-phonon interaction. Our data
<> disagree with the macroscopic models of electron-phonon
<> interaction, but they are in excellent agreement with the
<> microscopic model proposed recently by Huang and Zhu.
<> KP: RAMAN-SCATTERING, CONFINED LO, GAAS, SUPERLATTICES
<>
<> (24) TI: PHONON-ASSISTED TUNNELING DUE TO LOCALIZED MODES IN DOUBLE-
<> BARRIER STRUCTURES
<> AU: TURLEY_PJ, TEITSWORTH_SW
<> NA: DUKE UNIV,DEPT PHYS,DURHAM,NC,27706
<> JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1991, Vol.44, No.15,
<> pp.8181-8184
<> AB: The excess current associated with phonon-assisted tunneling at
<> low temperature in GaAs/AlAs double-barrier resonant-tunneling
<> structures is calculated taking into account localized phonon
<> modes. We find that symmetric interface phonon modes generate
<> the most current in a typical structure, while confined modes
<> in the GaAs well also contribute significantly. Antisymmetric
<> interface modes and confined modes in AlAs barrier layers
<> generate much less current. Numerical results are in
<> unexpectedly close agreement with available experimental data.
<> KP: QUANTUM WELLS, HETEROSTRUCTURES, SUPERLATTICES, SCATTERING,
<> EMISSION, FIELD
<>
<> (25) TI: ELECTRON-PHONON INTERACTION IN 2-DIMENSIONAL SYSTEMS - A
<> MICROSCOPIC APPROACH
<> AU: LUGLI_P, MOLINARI_E, RUCKER_H
<> NA: UNIV ROME 2,DIPARTIMENTO INGN MECCAN,I-00173 ROME,ITALY
<> CNR,IST OM CORBINO,I-00189 ROME,ITALY
<> HUMBOLDT UNIV,FACHBEREICH PHYS,O-1040 BERLIN,GERMANY
<> JN: SUPERLATTICES AND MICROSTRUCTURES, 1991, Vol.10, No.4, pp.471-
<> 478
<> KP: SEMICONDUCTOR QUANTUM-WELLS, GAAS-ALAS SUPERLATTICES, GAAS/ALAS
<> SUPERLATTICES, DOUBLE HETEROSTRUCTURES, OPTICAL PHONONS,
<> INTERFACE MODES, CONFINED LO, SCATTERING, DYNAMICS, SPECTRA
<>
<> (26) TI: HIGH-TEMPERATURE HOLE MOBILITY IN STRAINED QUANTUM-WELLS
<> AU: LAIKHTMAN_B
<> NA: HEBREW UNIV JERUSALEM,RACAH INST PHYS,JERUSALEM,ISRAEL
<> JN: APPLIED PHYSICS LETTERS, 1991, Vol.59, No.23, pp.3021-3023
<> AB: Strained quantum wells are promising candidates on high-speed
<> p-channel field-effect transistors (FET) because of a low
<> effective mass in the split valence band. Here for the first
<> time the high-temperature mobility of holes is studied taking
<> into account realistic wave functions of split light mass
<> subband. The main limit to the mobility at high temperature is
<> put by LO phonons and only this scattering mechanism is
<> considered here. It is shown that deformation coupling with
<> optical phonons is small in quantum wells with a large
<> splitting between the light- and heavy-hole subbands.
<> Analytical expression for the mobility is obtained. Numerical
<> estimates give the upper limit for the mobility as high as a
<> few thousand cm2/V s.
<> KP: OPTICAL-PHONON INTERACTION, III-V-COMPOUNDS, DOUBLE
<> HETEROSTRUCTURES, FROHLICH INTERACTION, ELECTRON, SCATTERING,
<> TRANSPORT, SUPERLATTICE, SINGLE, GAAS
<>
<> (27) TI: EFFECTS OF LOCALIZED PHONON MODES ON MAGNETOTUNNELING SPECTRA
<> IN DOUBLE-BARRIER STRUCTURES
<> AU: TURLEY_PJ, TEITSWORTH_SW
<> NA: DUKE UNIV,DEPT PHYS,DURHAM,NC,27706
<> JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1991, Vol.44, No.23,
<> pp.12959-12963
<> AB: The effects of localized phonon modes on the low-temperature
<> current-voltage curves of GaAs/AlAs double-barrier resonant-
<> tunneling structures have been calculated in the presence of
<> large magnetic fields parallel to the applied electric field.
<> The applied magnetic field sharpens and increases the height of
<> the phonon-assisted-tunneling peaks in agreement with
<> experimental data. Computed magnetotunneling spectra reveal
<> systematic deviations from a simple fan structure-also observed
<> experimentally-which are attributed here to oscillations of the
<> emitter Fermi level with the magnetic field.
<> KP: HETEROSTRUCTURES, EMISSION, FIELD
<>
<> (28) TI: MACROSCOPIC BEHAVIOR OF LONGITUDINAL OPTICAL PHONONS IN A
<> ALAS/GAAS/ALAS QUANTUM-WELL
<> AU: ZIANNI_X, BUTCHER_PN, DHARSSI_I
<> NA: UNIV WARWICK,DEPT PHYS,COVENTRY CV4 7AL,W MIDLANDS,ENGLAND
<> JN: JOURNAL OF PHYSICS-CONDENSED MATTER, 1992, Vol.4, No.6, pp.L
<> 77-L 83
<> IS: 0953-8984
<> DT: Letter
<> AB: Calculation of longitudinal optical (Lo) mode potential
<> functions and dispersion curves are made for a AlAs/GaAs/AlAs
<> quantum well using a macroscopic model. The interface boundary
<> conditions employed are continuity of potential and normal
<> components of both electric flux density and relative ionic
<> displacement. In the non-dispersive limit the model yields
<> unique potential functions of two types: confined modes and
<> interface modes. The confined mode potential functions are
<> almost identical to those calculated for a microscopic model by
<> Huang and Zhu. The interface modes are identical to those
<> predicted by both the microscopic model and the dielectric
<> continuum model. The introduction of bulk dispersion in GaAs
<> produces modes which are hybrids of the confined and interface
<> phonons.
<> KP: SUPERLATTICES, HETEROSTRUCTURES
<>
<> (29) TI: CALCULATED CONTRIBUTION OF LOCALIZED LO PHONON MODES TO THE
<> VALLEY CURRENT OF A DOUBLE-BARRIER DIODE
<> AU: NOGARET_A, PORTAL_JC
<> NA: INST NATL SCI APPL,LAB PHYSICOCHIM SOLIDES,F-31077
<> TOULOUSE,FRANCE
<> SNCI,CNRS,F-38042 GRENOBLE,FRANCE
<> JN: SURFACE SCIENCE, 1992, Vol.263, No.1-3, pp.234-239
<> IS: 0039-6028
<> AB: We have calculated the form factor and the current density
<> assisted by bulk and localised LO phonon emission in an ideal
<> case of a double-barrier diode (DBD). The transmission rate
<> from emitter to collector is given by the transfer Hamiltonian
<> approximation. We extend the formalism developped by Chevoir
<> and Vinter by calculating the matrix elements using the
<> appropriate electron-optical interaction Hamiltonians. We
<> compute the relevant form factors and valley currents versus
<> the applied voltage in the GaAs/Ga0.6Al0.4As system. We discuss
<> the coupling dependence upon the phonon emission parameters and
<> notably show the importance of zone center emission to explain
<> the emergence and sharpening of the replica peaks in the
<> current. Finally, evidence is given for a strong dependence of
<> the amplitude of the second AlAs phonon satellite as a function
<> of the emitter barrier width.
<> KP: DOUBLE HETEROSTRUCTURES, EMISSION
<>
<> (30) TI: HOT-ELECTRON RELAXATION IN SEMICONDUCTOR QUANTUM WIRES - BULK-
<> LO-PHONON EMISSION
<> AU: CAMPOS_VB, DASSARMA_S
<> NA: UNIV MARYLAND,DEPT PHYS,JOINT PROGRAM ADV ELECTR MAT,COLLEGE
<> PK,MD,20742
<> UNIV FED SAO CARLOS,DEPT FIS,BR-13560 SAO CARLOS,SP,BRAZIL
<> JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1992, Vol.45, No.7,
<> pp.3898-3901
<> IS: 0163-1829
<> DT: Note
<> AB: We calculate, within the electron-temperature model, the rate
<> of energy loss due to bulk-LO phonon emission from a hot-
<> electron gas to a cold lattice in quasi-one-dimensional GaAs
<> quantum-wire structures. Our theory includes the known
<> important physical mechanisms, such as degeneracy, dynamical
<> screening, quantum confinement, and the hot-phonon bottleneck
<> effect. In the experimentally interesting electron-temperature
<> range of 50-200 K, we find the hot-phonon effect to be
<> quantitatively the most significant physical mechanism
<> determining hot-electron energy relaxation. The typical
<> intrasubband relaxation time is of the order of a picosecond,
<> quite comparable to that found in two-dimensional quantum-well
<> structures.
<> KP: INVERSION CHANNELS, ENERGY, WELLS, SPECTROSCOPY, EXCITATIONS,
<> CARRIERS, SINGLE
<>
<> (31) TI: PICOSECOND TIME-RESOLVED RAMAN STUDIES OF ELECTRON-OPTICAL
<> PHONON INTERACTIONS IN ULTRATHIN GAAS-AIA MULTIPLE QUANTUM-WELL
<> STRUCTURES
<> AU: TSEN_KT
<> NA: ARIZONA STATE UNIV,DEPT PHYS,TEMPE,AZ,85287
<> JN: SEMICONDUCTOR SCIENCE AND TECHNOLOGY, 1992, Vol.7, No.3B, pp.B
<> 191-B 194
<> IS: 0268-1242
<> AB: Electron-optical phonon interactions in ultrathin GaAs-AlAs
<> multiple quantum well structures have been studied by using
<> picosecond time-resolved Raman spectroscopy. Our experimental
<> results have shown that the electrons primarily relax the
<> emission of interface optical phonons and that the electrons
<> interact not only with GaAs-like interface phonons but also
<> with AlAs-like interface phonons. The interaction strength of
<> electrons with AlAs-like interface phonons has been shown to be
<> much stronger than that of electrons with GaAs-like interface
<> phonons for ultrathin GaAs quantum wells. The strength of
<> electron-AlAs-like interface phonon interaction has been
<> demonstrated to decrease very rapidly as the thickness of the
<> GaAs well increases.
<> KP: DOUBLE HETEROSTRUCTURES, SEMICONDUCTOR HETEROJUNCTIONS, POLAR
<> SCATTERING, TRANSPORT, SUPERLATTICES, MOBILITY, LAYERS, RATES
<>
<> (32) TI: FUCHS-KLIEWER INTERFACE POLARITONS AND THEIR INTERACTIONS WITH
<> ELECTRONS IN GAAS/ALAS DOUBLE HETEROSTRUCTURES
<> AU: ALDOSSARY_O, BABIKER_M, CONSTANTINOU_NC
<> NA: UNIV ESSEX,DEPT PHYS,COLCHESTER CO4 3SQ,ESSEX,ENGLAND
<> JN: SEMICONDUCTOR SCIENCE AND TECHNOLOGY, 1992, Vol.7, No.3B, pp.B
<> 91-B 93
<> IS: 0268-1242
<> AB: A new theoretical approach to describe the interaction of
<> electrons with Fuchs-Kliewer (FK) interface phonon polaritons
<> is outlined. The quantized vector potential A of the FK modes
<> in GaAs/AlAs quantum wells is derived and employed via the
<> minimal coupling interaction (-e/m*)A.p to evaluate the
<> intersubband and intrasubband relaxation rates. A novel
<> resonance in the intersubband rate is predicted and shown to be
<> intimately related to the FK mode dispersion. As for the
<> intrasubband rate, it is shown that for small well widths the
<> AlAs-like FK interface mode is crucial for relaxing the carrier
<> energy in GaAs/AlAs systems.
<> KP: PHONON INTERACTION, QUANTUM-WELL, SCATTERING
<>
<> (33) TI: EFFECTS OF ELECTRON INTERFACE-PHONON INTERACTION ON RESONANT
<> TUNNELING IN DOUBLE-BARRIER HETEROSTRUCTURES
<> AU: MORI_N, TANIGUCHI_K, HAMAGUCHI_C
<> NA: OSAKA UNIV,DEPT ELECTR ENGN,2-1 YAMADA OKA,SUITA,OSAKA
<> 565,JAPAN
<> JN: SEMICONDUCTOR SCIENCE AND TECHNOLOGY, 1992, Vol.7, No.3B, pp.B
<> 83-B 87
<> IS: 0268-1242
<> AB: The tunnelling current through a resonant tunnelling structure
<> is calculated including electron-interface-phonon coupling in
<> the quantum well. The Hamiltonian describing electron-phonon
<> interaction in a double-barrier structure is derived using the
<> dielectric continuum model. Our result shows that interface
<> phonons of the barrier play a significant role in the double-
<> barrier structure whose barrier width is greater than the well
<> width.
<>
<> (34) TI: ELECTRON PHONON INTERACTION IN SEMICONDUCTOR SUPERLATTICES
<> AU: TSUCHIYA_T, ANDO_T
<> NA: UNIV TOKYO,INST SOLID STATE PHYS,MINATO KU,TOKYO 106,JAPAN
<> JN: SEMICONDUCTOR SCIENCE AND TECHNOLOGY, 1992, Vol.7, No.3B, pp.B
<> 73-B 76
<> IS: 0268-1242
<> AB: Scattering rates of electrons in GaAs/AlAs superlattices are
<> calculated in an envelope-function approximation which almost
<> completely reproduces long-wavelength optical phonons. The
<> results are compared with those obtained in the bulk-phonon
<> model and the dielectric continuum model, which shows that the
<> dielectric continuum model can provide an accurate estimate of
<> the strength of electron-phonon scattering and that even the
<> bulk-phonon model explains the layer thickness dependence
<> reasonably well. The underlying physics leading to this result
<> is discussed.
<> KP: GAAS-ALAS SUPERLATTICES, OPTICAL PHONONS, QUANTUM-WELL,
<> GAAS/ALAS SUPERLATTICES, SCATTERING, ANISOTROPY
<>
<> (35) TI: ELECTRON PHONON INTERACTIONS IN 2-DIMENSIONAL SYSTEMS - A
<> MICROSCOPIC APPROACH
<> AU: MOLINARI_E, BUNGARO_C, GULIA_M, LUGLI_P, RUCKER_H
<> NA: CNR,IST OM CORBINO,VIA CASSIA 1216,I-00189 ROME,ITALY
<> UNIV ROME,DIPARTIMENTO INGN ELETTR 2,I-00173 ROME,ITALY
<> HUMBOLDT UNIV,FACHBEREICH PHYS,O-1040 BERLIN,GERMANY
<> JN: SEMICONDUCTOR SCIENCE AND TECHNOLOGY, 1992, Vol.7, No.3B, pp.B
<> 67-B 72
<> IS: 0268-1242
<> AB: The electron-optical-phonon scattering rates in GaAs/AlAs
<> quantum wells (QW) are calculated on the basis of a fully
<> microscopic description of the phonon spectrum. The results
<> indicate the great importance of confined as well as GaAs-like
<> and AlAs-like interface phonons. The implications of these
<> findings are discussed by using the calculated rates in Monte
<> Carlo simulations of ultrafast carrier relaxation in a 50
<> angstrom QW.
<> KP: SEMICONDUCTOR QUANTUM-WELLS, GAAS-ALAS SUPERLATTICES, ENERGY-
<> LOSS RATES, GAAS/ALAS SUPERLATTICES, DOUBLE HETEROSTRUCTURES,
<> SCATTERING, MODES, CARRIERS, DYNAMICS
<>
<> (36) TI: CONFINED PHONON MODES AND HOT-ELECTRON ENERGY RELAXATION IN
<> SEMICONDUCTOR MICROSTRUCTURES
<> AU: DASSARMA_S, CAMPOS_VB, STROSCIO_MA, KIM_KW
<> NA: UNIV MARYLAND,DEPT PHYS,JOINT PROGRAM ADV ELECTR MAT,COLLEGE
<> PK,MD,20742
<> USA,RES OFF,RES TRIANGLE PK,NC,27709
<> N CAROLINA STATE UNIV,DEPT ELECT & COMP ENGN,RALEIGH,NC,27695
<> JN: SEMICONDUCTOR SCIENCE AND TECHNOLOGY, 1992, Vol.7, No.3B, pp.B
<> 60-B 66
<> IS: 0268-1242
<> AB: The role of confined phonon modes in determining the energy
<> relaxation of hot electrons in low-dimensional semiconductor
<> microstructures is discussed within a dielectric continuum
<> model for the LO phonon confinement and a long wavelength
<> Frohlich model for the electron-phonon interaction. Numerical
<> results are provided for the hot-electron relaxation rate as a
<> function of electron temperature and density for GaAs quantum
<> wells and quantum wires by taking into account emission of slab
<> phonon modes. Comparison with existing experimental results
<> shows some evidence for slab phonon emission in intersubband
<> electronic relaxation in reasonably narrow quantum wells. It is
<> argued that most experiments can be interpreted in terms of an
<> electron-bulk phonon interaction model (i.e. by taking into
<> account the effect of confinement only on the electrons and
<> assuming the phonons to be the usual bulk three-dimensional
<> phonons) because a number of important physical processes, such
<> as screening, the hot phonon effect, phonon self-energy
<> correction etc, make it difficult to distinguish quantitatively
<> between various models for phonon confinement, except perhaps
<> in the narrowest (< 50 angstrom) wells and wires. Detailed
<> numerical results for the calculated intra-subband relaxation
<> rate in GaAs quantum wires are provided within the slab phonon
<> and the electron temperature model, including the effects of
<> dynamical screening, quantum degeneracy and non-equilibrium hot
<> phonons.
<> KP: GAAS QUANTUM WELLS, RESOLVED RAMAN-SCATTERING, WAVELENGTH
<> OPTICAL PHONONS, LO PHONONS, INTERSUBBAND RELAXATION, DOUBLE
<> HETEROSTRUCTURES, ALAS SUPERLATTICES, EXCITATIONS, WIRE,
<> POLARIZABILITY
<>
<> (37) TI: COUPLING OF POLAR OPTICAL PHONONS TO ELECTRONS IN SUPERLATTICES
<> AND ISOLATED QUANTUM-WELLS
<> AU: BABIKER_M
<> NA: UNIV ESSEX,DEPT PHYS,WIVENHOE PK,COLCHESTER CO4
<> 3SQ,ESSEX,ENGLAND
<> JN: SEMICONDUCTOR SCIENCE AND TECHNOLOGY, 1992, Vol.7, No.3B, pp.B
<> 52-B 59
<> IS: 0268-1242
<> AB: Theoretical models that treat optical lattice vibrations in
<> heterostructures by viewing the lattice-matched crystalline
<> media as isotropic homogeneous continua separated by smooth
<> planar interfaces, offer conceptual simplicity and are, without
<> doubt, computationally advantageous when calculations involving
<> electron-phonon interactions are carried out. The two
<> (apparently conflicting) continuum models, namely the
<> hydrodynamic (HD) and the electromagnetic (EM) models, are
<> discussed, their calculational frameworks in the context of
<> semiconductor heterostructures examined and some of their
<> predictions displayed. A statement of the HD model in terms of
<> a polariton subset plus an LO subset is given, and this permits
<> a transparent comparison with the EM model to be made. It is
<> then shown that the EM model is a non-dispersive, non-retarded
<> and subsequently mishandled version of the polariton subset of
<> the HD model and it completely disallows proper considerations
<> of longitudinal optical modes. The sources of the current
<> controversies concerning HD versus EM boundary conditions-
<> confined mode identification, existence of localized alloy
<> interface LO modes and interface FK modes, Frohlich-type
<> coupling e-PHI together with the e-phi versus - (e/m*c)A(T).p
<> couplings to electrons-are all pointed out and discussed. A
<> close agreement between some very recent predictions of the two
<> models concerning interface mode contributions to energy
<> relaxation is explained and this helps to clarify the nature of
<> the conflict regarding other contributions. Further evidence in
<> support of the HD model from recent theoretical and
<> experimental results is pointed out.
<> KP: GAAS-ALAS SUPERLATTICES, SEMICONDUCTOR SUPERLATTICES, PERIOD
<> SUPERLATTICES, CARRIER RELAXATION, EFFECTIVE-MASS, CONFINED LO,
<> HETEROSTRUCTURES, SCATTERING, SINGLE, TRANSITIONS
<>
<> (38) TI: TRANSITION FROM LO-PHONON TO SO-PHONON SCATTERING IN MESOSCALE
<> STRUCTURES
<> AU: KIM_KW, LITTLEJOHN_MA, STROSCIO_MA, IAFRATE_GJ
<> NA: N CAROLINA STATE UNIV,DEPT ELECT & COMP ENGN,RALEIGH,NC,27695
<> USA,RES OFF,RES TRIANGLE PK,NC,27709
<> JN: SEMICONDUCTOR SCIENCE AND TECHNOLOGY, 1992, Vol.7, No.3B, pp.B
<> 49-B 51
<> IS: 0268-1242
<> AB: Macroscopic dielectric continuum models of optical-phonon modes
<> predict enhancements in the magnitudes of the surface-optical
<> (SO) modes in double-barrier heterostructures as the
<> heterojunction-to-heterojunction separation is reduced. In this
<> paper, the ratio of electron scattering by the SO-phonon modes
<> to that by the (electrostatic) confined longitudinal-optical-
<> (LO-) phonon modes is calculated for a GaAs/AlAs short-period
<> superlattice based on the assumption that electron-SO-phonon
<> scattering may be described by a scalar potential. The scaling
<> of the ratio of electron-SO-phonon scattering to electron-LO-
<> phonon scattering as a function of the superlattice period
<> provides a sensitive test of the appropriateness of the scalar-
<> potential model. The effect of phonon confinement on electron-
<> optical-phonon scattering rates is presented for rectangular
<> quantum wires as well. A major conclusion of these new results
<> is that it is essential to model phonon confinement properly in
<> predicting carrier transport properties in mesoscale
<> structures.
<> KP: RECTANGULAR QUANTUM WIRE, ELECTRONIC POLARIZABILITY, DOUBLE
<> HETEROSTRUCTURES, FROHLICH INTERACTION, SUPERLATTICES, MODES
<>
<> (39) TI: MICROSCOPIC CALCULATION OF THE ELECTRON-PHONON INTERACTION IN
<> QUANTUM-WELLS
<> AU: RUCKER_H, MOLINARI_E, LUGLI_P
<> NA: HUMBOLDT UNIV,FACHBEREICH PHYS,INVALIDENSTR 110,O-1040
<> BERLIN,GERMANY
<> IST OM CORBINO,CNR,I-00189 ROME,ITALY
<> UNIV ROME 2,DIPARTIMENTO INGN ELECTR,I-00173 ROME,ITALY
<> JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1992, Vol.45, No.12,
<> pp.6747-6756
<> IS: 0163-1829
<> AB: The electron-optical-phonon scattering rates in GaAs/AlAs
<> quantum wells are calculated on the basis of a fully
<> microscopic description of the phonon spectra. The results
<> indicate the great importance of confined as well as GaAs-like
<> and AlAs-like interface phonons. By comparing our results with
<> those of several macroscopic models, we resolve a long-standing
<> controversy on their ability to describe the relevant
<> vibrations.
<> KP: GAAS-ALAS SUPERLATTICES, ENERGY-LOSS RATES, DOUBLE
<> HETEROSTRUCTURES, GAAS/ALAS SUPERLATTICES, FROHLICH INTERACTION,
<> OPTICAL PHONONS, INTERFACE MODES, HOT CARRIERS, CONFINED LO,
<> SCATTERING
<>
<> (40) TI: MICROSCOPIC BASIS FOR A SUM-RULE FOR POLAR-OPTICAL-PHONON
<> SCATTERING OF CARRIERS IN HETEROSTRUCTURES
<> AU: REGISTER_LF
<> NA: UNIV ILLINOIS,BECKMAN INST,URBANA,IL,61801
<> UNIV ILLINOIS,COORDINATED SCI LAB,URBANA,IL,61801
<> JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1992, Vol.45, No.15,
<> pp.8756-8759
<> IS: 0163-1829
<> DT: Note
<> AB: A fully microscopic model of the carrier-phonon interaction is
<> employed to obtain a sum rule for polar-optical-phonon
<> scattering of carriers in semiconductor heterostructures. In
<> 1989, Mori and Ando, considering diatomic polar semiconductors
<> and using a dielectric continuum model to derive the phonon
<> modes, derived a sum rule for the carrier-polar-optical-phonon
<> interaction in single and double planar heterostructures that
<> related and constrained the partial contribution from each
<> branch of the optical-phonon spectrum to the total interaction.
<> Here again such a sum rule is derived, but this work differs in
<> two important ways: (1) Fully microscopic models of the phonons
<> and the carrier-phonon interaction are employed, and (2) the
<> results are valid for any semiconductor heterostructure
<> regardless of geometry or materials, including alloy and
<> nonpolar constituents. It is demonstrated that this sum rule
<> reproduces the usual scattering-rate result in the bulk-crystal
<> limit. The derivation of this sum rule requires no assumptions
<> about the functional form of the phonon modes; rather it
<> employs only the inherent orthogonality and mathematical
<> completeness of the classical vibrational modes over the
<> crystal-lattice degrees of freedom, relationships valid for any
<> harmonically coupled system of particles. Thus this work
<> provides independent theoretical support for the sum rule of
<> Mori and Ando and extends the sum rule to arbitrary
<> heterostructure geometries and nonmetallic materials.
<> KP: ELECTRON
<>
<> (41) TI: ELECTRON-MOBILITY ENHANCEMENT BY CONFINING OPTICAL PHONONS IN
<> GAAS/ALAS MULTIPLE QUANTUM-WELLS
<> AU: ZHU_XT, GORONKIN_H, MARACAS_GN, DROOPAD_R, STROSCIO_MA
<> NA: MOTOROLA INC,PHOENIX CORP RES LABS,TEMPE,AZ,85284
<> ARIZONA STATE UNIV,DEPT ELECT ENGN,TEMPE,AZ,85287
<> USA,RES OFF,RES TRIANGLE PK,NC,27709
<> JN: APPLIED PHYSICS LETTERS, 1992, Vol.60, No.17, pp.2141-2143
<> IS: 0003-6951
<> AB: We report experimental evidence for an enhanced electron
<> mobility in a multiple quantum well structure in which the
<> optical phonon modes are confined. By inserting n ultrathin
<> layers of AlAs into a host GaAs well, thus dividing the
<> bulklike host well into n + 1 miniwells, we observe a
<> substantial enhancement in electron mobility for temperatures T
<> <> 100 K. We have also studied the dependence of the electron
<> mobility on the miniwell width. The electron mobility is found
<> to first increase with decreasing miniwell width and then
<> decrease after reaching a maximum value at the width around 45
<> angstrom.
<> KP: DOUBLE HETEROSTRUCTURES, FROHLICH INTERACTION, SCATTERING
<>
<> (42) TI: INTERSUBBAND RELAXATION DYNAMICS IN TERNARY BINARY QUANTUM-
<> WELLS - ROLE OF THE ELECTRON-OPTICAL PHONON INTERACTION
<> AU: JOSHI_RP
<> NA: OLD DOMINION UNIV,DEPT ELECT & COMP ENGN,NORFOLK,VA,23529
<> JN: JOURNAL OF APPLIED PHYSICS, 1992, Vol.71, No.8, pp.3827-3835
<> IS: 0021-8979
<> AB: Ensemble Monte Carlo calculations of the intersubband dynamics
<> in binary-ternary double-heterostructure systems are presented.
<> The presence of a ternary alloy has been explicitly
<> incorporated to account for complexities arising from the
<> multimode nature of phonons in real heterostructures.
<> Electronic scattering rates are derived as a function of energy
<> and quantum-well width for both confined and interface modes on
<> the basis of a continuum model. Results of Monte Carlo
<> simulations yield an intersubband time constant that is in
<> reasonable agreement with the experimental value, but only when
<> details of the phonon modes and their dispersion, spreading of
<> the electronic wave functions due to poor confinement, and the
<> phonon amplification effects are comprehensively included.
<> KP: RESOLVED RAMAN-SCATTERING, DOUBLE HETEROSTRUCTURES, FROHLICH
<> INTERACTION, PHOTOEXCITED GAAS, SUPER-LATTICES, SUPERLATTICES,
<> TRANSPORT, SYSTEMS, MODES, SEMICONDUCTORS
<>
<> (43) TI: DRAMATIC REDUCTION IN THE LONGITUDINAL-OPTICAL PHONON EMISSION
<> RATE IN POLAR-SEMICONDUCTOR QUANTUM WIRES
<> AU: STROSCIO_MA, KIM_KW, IAFRATE_GJ, DUTTA_M, GRUBIN_HL
<> NA: USA,RES OFF,POB 12211,RES TRIANGLE PK,NC,27709
<> N CAROLINA STATE UNIV,DEPT ELECT & COMP ENGN,RALEIGH,NC,27695
<> USA,ELECTR TECHNOL & DEVICES LAB,FT MONMOUTH,NJ,07703
<> SCI RES ASSOCIATES ING,GLASTONBURY,CT,06033
<> JN: PHILOSOPHICAL MAGAZINE LETTERS, 1992, Vol.65, No.4, pp.173-176
<> IS: 0950-0839
<> AB: Novel quantum-effect polar-semiconductor structures underlie
<> technologies portending dramatic enhancements in the capability
<> to process information orders of magnitude faster than is
<> possible currently. In many embodiments of these quantum-effect
<> structures, charges are transported in quasi-one-dimensional
<> quantum wires which must support the transport of charges at
<> high mobilities. However, it has recently been demonstrated
<> that the longitudinal-optical (LO) phonons established at
<> quantum-wire interfaces lead to dramatic enhancements in
<> carrier-phonon interactions and concomitant degradation in
<> carrier mobility. This letter demonstrates that phonon modes
<> may be tailored through the judicious use of metal-
<> semiconductor interfaces in such a way as to dramatically
<> reduce unwanted emission of interface LO phonons and,
<> consequently, to lead to the achievement of high quantum-wire
<> mobility.
<> KP: HETEROSTRUCTURES, GROWTH, SCATTERING, ELECTRONS, SYSTEM
<>
<> (44) TI: EFFECTS OF ELECTRON-INTERFACE-PHONON INTERACTIONS ON
<> MAGNETOPOLARONIC IMPURITY TRANSITIONS IN QUANTUM-WELLS
<> AU: CHEN_R, LIN_DL, GEORGE_TF
<> NA: SUNY BUFFALO,DEPT PHYS & ASTRON,BUFFALO,NY,14260
<> WASHINGTON STATE UNIV,DEPT PHYS,PULLMAN,WA,99164
<> WASHINGTON STATE UNIV,DEPT CHEM,PULLMAN,WA,99164
<> JN: CHINESE JOURNAL OF PHYSICS, 1992, Vol.30, No.2, pp.165-176
<> IS: 0577-9073
<> AB: Electron interactions with interface phonon modes and strictly-
<> confined bulk phonon modes are considered for the first time to
<> calculate the magnetopolaronic effect on the transition energy
<> of a hydrogenic impurity in the quantum well of a double
<> heterostructure. The electron-phonon interaction is treated as
<> a perturbation on a hydrogenic impurity confined in a quantum
<> well under strong magnetic fields. The unperturbed states are
<> obtained by the variational method with trial wave functions
<> constructed on symmetry considerations. It is found that the
<> transition energy, as a function of the applied magnetic field,
<> breaks up into three branches with two interaction gaps
<> occuring at two-level and three-level resonances. The lowest
<> branch lies below the bulk TO energy. These results are found
<> in good agreement with recent experimental data.
<> KP: GAAS-ALAS SUPERLATTICES, DOUBLE HETEROSTRUCTURES, FROHLICH
<> INTERACTION, MODES
<>
<> (45) TI: ANALYSIS OF THE PHENOMENOLOGICAL MODELS FOR LONG-WAVELENGTH
<> POLAR OPTICAL MODES IN SEMICONDUCTOR LAYERED SYSTEMS
<> AU: TRALLEROGINER_C, GARCIAMOLINER_F, VELASCO_VR, CARDONA_M
<> NA: MAX PLANCK INST FESTKORPERFORSCH,HEISENBERGSTR 1,W-7000
<> STUTTGART 80,GERMANY
<> CSIC,INST CIENCIA MAT,E-28006 MADRID,SPAIN
<> UNIV HAVANA,DEPT THEORET PHYS,HAVANA,CUBA
<> JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1992, Vol.45, No.20,
<> pp.11944-11948
<> IS: 0163-1829
<> AB: The standard type of phenomenological model for this problem
<> consists of a mechanical field equation for the vibration
<> amplitude and-in the quasistatic limit-Poisson's equation. The
<> critical issue concerns the matching boundary conditions. The
<> apparent incompatibility between mechanical and electrostatic
<> boundary conditions often appearing in the literature is
<> analyzed and clarified. It is shown how the full solution can
<> be obtained so that there is no incompatibility and the key
<> features of the results, notably the symmetry pattern, agree
<> with microscopic calculations and with Raman-scattering data.
<> KP: GAAS/ALAS SUPERLATTICES, CONFINED LO, PHONONS, HETEROSTRUCTURES,
<> SCATTERING
<>
<> (46) TI: SUPPRESSION OF EXCITON-PHONON SCATTERING IN QUASI-ONE-
<> DIMENSIONAL SYSTEMS
<> AU: NOJIMA_S
<> NA: NIPPON TELEGRAPH & TEL PUBL CORP,OPTOELECTR LABS,3-1 MORINOSATO
<> WAKAMIYA,ATSUGI,KANAGAWA 24301,JAPAN
<> JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1992, Vol.46, No.4,
<> pp.2302-2311
<> IS: 0163-1829
<> AB: Calculations have been made of the linewidth due to LO-phonon
<> scattering of excitons in quasi-onedimensional (Q1D) systems,
<> which is thought to be the dominant factor in homogeneous
<> broadening of excitonic absorption lines at room temperature.
<> Three kinds of suppression effects for exciton-phonon
<> scattering have been isolated, all of which appear to be
<> achieved in the most pronounced manner in Q1D systems: first by
<> fabricating smaller structures, second by the presence of a
<> Coulomb field between electron and hole in the dissociated
<> exciton, and third by possessing close mass values for electron
<> and hole. It is demonstrated, in particular, as a hypothetical
<> example that an exciton state can be achieved by combining the
<> above effects, which is free from phonon scattering at room
<> temperature.
<> KP: QUANTUM-WELL STRUCTURES, NONLINEAR-OPTICAL-PROPERTIES, LATERAL
<> CONFINEMENT, BINDING-ENERGY, WIRES, LINEWIDTHS, STATES
<>
<> (47) TI: PHONON-CONFINEMENT EFFECT ON ELECTRON-ENERGY LOSS IN ONE-
<> DIMENSIONAL QUANTUM WIRES
<> AU: CAMPOS_VB, DASSARMA_S, STROSCIO_MA
<> NA: UNIV MARYLAND,DEPT PHYS,JOINT PROGRAM ADV ELECTR MAT,COLL
<> PK,MD,20742
<> USA,RES OFF,RES TRIANGLE PK,NC,27709
<> UNIV FED SAO CARLOS,DEPT FIS,BR-13560 SAO CARLOS,SP,BRAZIL
<> JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1992, Vol.46, No.7,
<> pp.3849-3853
<> IS: 0163-1829
<> AB: We calculate, within the electron-temperature model, hot-
<> electron intrasubband energy relaxation rates via LO-phonon
<> emission in GaAs quantum wires, taking into account quantum
<> degeneracy, dynamical screening, hot-phonon bottleneck, and, in
<> particular, phonon confinement. Two prevailing macroscopic
<> models of phonon confinement, namely, the slab or the
<> electrostatic model and the guided or the mechanical model, are
<> compared quantitatively. We find that the slab model, while
<> giving relaxation rates comparable to the bulk-phonon emission
<> rates, leads to an order of magnitude faster relaxation than
<> the guided model. For reasonable parameter values, the hot-
<> phonon-bottleneck effect is found to be the single most
<> important physical mechanism determining energy relaxation.
<> Numerical values for electronic-energy-loss rates in GaAs
<> quantum wires are provided for both models of phonon
<> confinement for a range of values of the relevant parameters,
<> including confinement size, carrier density, hot-phonon
<> lifetime, and electron temperature.
<> KP: DOUBLE HETEROSTRUCTURES, RELAXATION, WELLS, SCATTERING, SYSTEMS,
<> GAS
<>
<> (48) TI: THEORY OF LOCALIZED PHONON MODES AND THEIR EFFECTS ON ELECTRON-
<> TUNNELING IN DOUBLE-BARRIER STRUCTURES
<> AU: TURLEY_PJ, TEITSWORTH_SW
<> NA: DUKE UNIV,DEPT PHYS,DURHAM,NC,27706
<> JN: JOURNAL OF APPLIED PHYSICS, 1992, Vol.72, No.6, pp.2356-2366
<> IS: 0021-8979
<> AB: The role of localized phonon modes in phonon-assisted tunneling
<> in GaAs/AlAs double-barrier resonant tunneling structures is
<> considered for a range of temperatures and magnetic fields.
<> Phonon modes are calculated using a dielectric continuum model
<> and electron-phonon Hamiltonians are presented for the most
<> important modes. Formulas for phonon-assisted tunneling
<> currents are derived that express the inherently three-
<> dimensional process in a simple one-dimensional form. It is
<> found that the excess current due to phonon-assisted tunneling
<> in typical structures is caused primarily by two types of
<> localized modes: confined modes in the well and symmetric
<> interface modes, with interface modes dominating in structures
<> with narrow wells. Current peaks broaden with increasing
<> temperature, and for temperatures grater than or similar to 20
<> K the resolution of features due to distinct phonon types is
<> very difficult. The application of a magnetic field parallel to
<> the current flow leads to a complex spectrum of sharp current
<> peaks corresponding to various inter-Landau-level transitions
<> which occur during phonon-assisted tunneling.
<> KP: SEMICONDUCTOR QUANTUM WELLS, POLAR-POLAR CRYSTALS, DOUBLE
<> HETEROSTRUCTURES, OPTICAL PHONONS, INELASTIC-SCATTERING,
<> FROHLICH INTERACTION, SLOW-ELECTRONS, SUPERLATTICES, INTERFACE,
<> EMISSION
<>
<> (49) TI: EFFECTS OF INTERFACE PHONON-SCATTERING IN MULTIHETEROINTERFACE
<> STRUCTURES
<> AU: KIM_KW, BHATT_AR, STROSCIO_MA, TURLEY_PJ, TEITSWORTH_SW
<> NA: N CAROLINA STATE UNIV,DEPT ELECT & COMP ENGN,RALEIGH,NC,27695
<> USA,RES OFF,RES TRIANGLE PK,NC,27709
<> DUKE UNIV,DEPT PHYS,DURHAM,NC,27706
<> JN: JOURNAL OF APPLIED PHYSICS, 1992, Vol.72, No.6, pp.2282-2287
<> IS: 0021-8979
<> AB: In this paper, the commonly used but idealistic formulation of
<> quantized optical-phonon modes for a heterostructure system
<> with only two heterojunctions (i.e., single quantum-well
<> structures) is extended to the more realistic case of
<> multiheterointerface structures. By applying the macroscopic
<> dielectric continuum approach, dispersion relations and
<> interaction Hamiltonians for interface-phonon modes are derived
<> for a double-barrier structure and scattering rates based on
<> these results are used to determine the range of practical
<> validity of the idealistic model using interaction Hamiltonians
<> appropriate for single quantum wells with infinite barrier
<> widths. It is found that when the dimensions of the structures
<> are larger than approximately 30 angstrom, this simplified
<> description can be applied to multiheterointerface structures
<> in general with reasonable accuracy.
<> KP: QUANTUM-WELL, ELECTRONIC POLARIZABILITY, DOUBLE
<> HETEROSTRUCTURES, FROHLICH INTERACTION, EMISSION, SYSTEMS,
<> VALLEY, MODES
<>
<> (50) TI: RAMAN-STUDY OF INTERFACE PHONONS IN GAAS/ALAS QUANTUM-WELLS -
<> RESONANCE WITH THE E2-H2 EXCITON
<> AU: FU_LP, SCHMIEDEL_T, PETROU_A, DUTTA_M, NEWMAN_PG, STROSCIO_MA
<> NA: SUNY BUFFALO,DEPT PHYS & ASTRON,BUFFALO,NY,14260
<> SUNY BUFFALO,CTR ELECTR & ELECTROOPT MAT,BUFFALO,NY,14260
<> USA,ELECTR TECHNOL & DEVICES LAB,FT MONMOUTH,NJ,07703
<> USA,RES OFF,RES TRIANGLE PK,NC,27709
<> JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1992, Vol.46, No.11,
<> pp.7196-7199
<> IS: 0163-1829
<> DT: Note
<> AB: We have performed light-scattering experiments from two
<> GaAs/AlAs quantum-well structures. In one sample, the second
<> conduction confinement subband e2 is near degenerate with the
<> AlAs X-band minimum. Raman spectra excited resonantly with the
<> e2-h2 transition contain phonon modes associated with both the
<> GaAs and the AlAs layers. The resonantly excited AlAs phonon
<> modes have an average frequency of 385 cm-1 whereas in
<> nonresonant Raman experiments the observed shift is 405 cm-1.
<> This indicates that the AlAs phonon spectra observed under
<> resonant conditions are dominated by interface modes. Resonant
<> Raman spectra from the second sample, in which the e2 State is
<> below the X-band minimum, contain only phonon modes associated
<> with the GaAs layers.
<> KP: GAAS-ALAS SUPERLATTICES, GAAS-ALXGA1-XAS SUPERLATTICES,
<> VIBRATIONAL-MODES, CONFINED LO, SCATTERING, HETEROSTRUCTURES
<>
<> (51) TI: SIZE DEPENDENCE OF THE THERMAL BROADENING OF THE EXCITON
<> LINEWIDTH IN GAAS/GA0.7AL0.3AS SINGLE QUANTUM-WELLS
<> AU: QIANG_H, POLLAK_FH, TORRES_CMS, LEITCH_W, KEAN_AH, STROSCIO_MA,
<> IAFRATE_GJ
<> NA: CUNY BROOKLYN COLL,DEPT PHYS,BROOKLYN,NY,11210
<> UNIV GLASGOW,DEPT ELECTR & ELECT ENGN,NANOELECTR RES
<> CTR,GLASGOW G12 8QQ,SCOTLAND
<> USA,RES OFF,RES TRIANGLE PK,NC,27709
<> N CAROLINA STATE UNIV,DEPT ELECT ENGN,RALEIGH,NC,27696
<> CUNY GRAD SCH & UNIV CTR,NEW YORK,NY,10036
<> JN: APPLIED PHYSICS LETTERS, 1992, Vol.61, No.12, pp.1411-1413
<> IS: 0003-6951
<> AB: We have studied the temperature dependence of the linewidth,
<> GAMMA(T), of the fundamental absorption edge in bulk GaAs and
<> four GaAs/Ga0.7Al0.3As single quantum wells of different well
<> width using photoreflectance. As a result of the size
<> dependence of the exciton-longitudinal optical phonon
<> interaction, the thermal broadening of the linewidth diminishes
<> as the dimensionality and size of the system are reduced.
<> KP: OPTICAL-PHONON INTERACTION, TEMPERATURE-DEPENDENCE, RAMAN-
<> SCATTERING, CRITICAL-POINTS, GAAS, HETEROSTRUCTURES,
<> SUPERLATTICES, SPECTRA, LO, GE
<>
<> (52) TI: NONLINEAR OPTICS IN COMPOSITE-MATERIALS .1. SEMICONDUCTOR AND
<> METAL CRYSTALLITES IN DIELECTRICS
<> AU: FLYTZANIS_C, HACHE_F, KLEIN_MC, RICARD_D, ROUSSIGNOL_P
<> NA: ECOLE POLYTECH,CNRS,OPT QUANT LAB,F-91128 PALAISEAU,FRANCE
<> JN: PROGRESS IN OPTICS, 1991, Vol.29, pp.321-411
<> IS: 0079-6638
<> DT: Review
<> KP: GLASS WAVE-GUIDES, SMALL SILVER PARTICLES, NON-LINEAR
<> REFRACTION, CDSSE-DOPED GLASS, CDSXSE1-X-DOPED GLASSES, AUGER
<> RECOMBINATION, PHASE CONJUGATION, ELECTRONIC PROPERTIES,
<> MEDIATED ENHANCEMENT, CUCL MICROCRYSTALS
<>
<> (53) TI: HOT PHOTOLUMINESCENCE IN QUANTUM-WELL STRUCTURES UNDER
<> CONTINUOUS WAVE PUMPING
<> AU: MIRLIN_DN, PEREL_VI
<> NA: AF IOFFE PHYSICOTECH INST,26 POLYTECHNICHESKAYA ST,ST
<> PETERSBURG 194021,USSR
<> JN: SEMICONDUCTOR SCIENCE AND TECHNOLOGY, 1992, Vol.7, No.10,
<> pp.1221-1229
<> IS: 0268-1242
<> DT: Review
<> AB: Recent results on recombination photoluminescence of hot
<> electrons and electron-hole pairs in quantum wells of the
<> GaAs/AlGaAs type are discussed. It is shown that linear
<> polarization of hot photoluminescence is due to the optical
<> alignment of two-dimensional (2D) electron momenta by linearly
<> polarized light. The times of intra- and intersubband
<> scattering of 2D electrons were determined from hot
<> luminescence depolarization in a magnetic field. The
<> intrasubband scattering times are found to be close to 150 fs
<> for the well widths from 50 to 100 angstrom. This agrees with a
<> calculation based on the assumption that 2D electrons are
<> scattered by bulk phonons, which is consistent with a
<> prediction from a dielectric continuum model. Experimental
<> dispersion dependences in the valence subbands of quantum wells
<> were first obtained from the hot photoluminescence spectra.
<> In a perpendicular magnetic field, which restricts hot carrier
<> motion in the quantum-well planes, radiation flares up due to
<> recombination of hot electrons and holes created by the same
<> light quantum (geminate recombination). Its spectral and
<> polarization properties depend noticeably on the magnetic field
<> and initial energy of hot carriers.
<> KP: DOUBLE HETEROSTRUCTURES, FROHLICH INTERACTION, SCATTERING, GAAS,
<> SEMICONDUCTORS, SPECTROSCOPY, PHONONS, SUPERLATTICES,
<> FEMTOSECOND, ELECTRONS
<>
<> (54) TI: ULTRAFAST FIELD-DEPENDENT RESPONSE OF BAND-EDGE PHOTOGENERATED
<> ELECTRONS IN QUANTUM-WELL STRUCTURES
<> AU: JOSHI_RP, GRONDIN_RO, ELGHAZALY_SM
<> NA: OLD DOMINION UNIV,DEPT ELECT & COMP ENGN,NORFOLK,VA,23529
<> ARIZONA STATE UNIV,CTR SOLID STATE ELECTR RES,TEMPE,AZ,85287
<> JN: IEEE JOURNAL OF QUANTUM ELECTRONICS, 1992, Vol.28, No.10,
<> pp.2456-2463
<> IS: 0018-9197
<> AB: We analyze the field-dependent femtosecond dynamics of bandedge
<> photogenerated electrons undergoing parallel transport in
<> quantum-well structures. The intracollisional field effect,
<> breakdown of the Fermi golden rule, quantization of the phonon
<> modes, and transient charge variations are all comprehensively
<> included. Our electron heating rates at zero fields are in
<> agreement with experiments. The results are indicative of an
<> adequate description of the electron-phonon interaction in two-
<> dimensional systems. At high fields we observe an energy
<> overshoot structure in keeping with recently observed data,
<> without any real-space transfer.
<> KP: DOUBLE HETEROSTRUCTURES, PHONON INTERACTION, TRANSPORT,
<> SEMICONDUCTORS, SCATTERING, SUPERLATTICES, TIME, EXCITATIONS,
<> DYNAMICS, PLASMAS
<>
<> (55) TI: MAGNETIC-FIELD ENHANCEMENT OF INTERFACE-PHONON EFFECTS ON
<> QUASI-2-DIMENSIONAL MAGNETOPOLARONS
<> AU: CHEN_R, LIN_DL, SHUKRI_M, CHEN_CY
<> NA: SUNY BUFFALO,DEPT PHYS & ASTRON,BUFFALO,NY,14260
<> CHINESE CTR ADV SCI & TECHNOL,WORLD LAB,BEIJING 100080,PEOPLES
<> R CHINA
<> GUANGZHOU TEACHERS COLL,DEPT PHYS,CANTON 510400,PEOPLES R CHINA
<> JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1992, Vol.46, No.20,
<> pp.13357-13362
<> IS: 0163-1829
<> AB: The binding energy of a polaron confined in the quantum well of
<> GaAs/Ga1-xAlxAs double heterostructures is calculated as a
<> function of the magnetic field applied in the direction of
<> growth. We have also calculated the oscillator strength of
<> electron-phonon interaction for transitions from various
<> excited states to the ground state of the polaron. Every type
<> of optical-phonon mode that can exist in such structures within
<> the continuum model is considered separately. It is found that
<> the magnetic field greatly enhances the interface-phonon part
<> of the polaron effect. For quantum wells of widths 150 angstrom
<> or smaller, the interface modes dominate all polaronic
<> phenomena we have encountered when B greater than or similar 1
<> T. For quantum wells of widths up to 100 angstrom,
<> contributions from confined bulk phonon modes are almost
<> negligible in magnetic fields B greater than or similar 1 T.
<> KP: DOUBLE HETEROSTRUCTURES, POLAR CRYSTALS, QUANTUM-WELLS, ENERGY
<>
<> (56) TI: ELECTRIC-FIELD INDUCED ULTRAFAST INTERSUBBAND TRANSITIONS IN
<> LARGE GAAS-ALAS QUANTUM-WELLS VIA ELECTRON-INTERFACE-PHONON
<> INTERACTION
<> AU: WEBER_G
<> NA: UNIV FED MINAS GERAIS,INST CIENCIAS EXATAS,DEPT FIS,CAIXA
<> POSTAL 702,BR-30161-970 BELO HORIZON,MG,BRAZIL
<> JN: SOLID STATE COMMUNICATIONS, 1992, Vol.84, No.6, pp.595-598
<> IS: 0038-1098
<> AB: We obtain the scattering times for intersubband transitions in
<> GaAs-AlAs quantum wells under the influence of an electric
<> field (parallel to the growth direction). The electron-
<> interface-phonon (Frohlich) interaction is taken into account
<> and scattering times faster than 100 fs are obtained for
<> quantum well widths between 150 angstrom and 160 angstrom.
<> KP: DOUBLE HETEROSTRUCTURES, SCATTERING RATES, SUPERLATTICES,
<> RELAXATION, STATES, SLAB
<>
<> (57) TI: INELASTIC ELECTRON RESONANT TUNNELING THROUGH A DOUBLE-BARRIER
<> NANOSTRUCTURE
<> AU: ZOU_NZ, CHAO_KA
<> NA: UNIV TRONDHEIM,NORWEGIAN INST TECHNOL,DEPT PHYS & MATH,DIV
<> PHYS,N-7034 TRONDHEIM,NORWAY
<> JN: PHYSICAL REVIEW LETTERS, 1992, Vol.69, No.22, pp.3224-3227
<> IS: 0031-9007
<> AB: The inelastic scattering effect on electron tunneling through a
<> double-barrier resonant tunneling device has been studied with
<> a cumulant expansion on the electron transmission probability
<> and the I-V characteristics using the Frohlich Hamiltonian
<> which allows electron recoil. The low-order expansion formula
<> used for numerical calculation satisfies a sum rule; its
<> analytical derivation is given here for the first time. As the
<> Fermi energy in the emitting lead is increased, electron recoil
<> enhances the incoherence process and so broadens the phonon
<> replica, which is also shifted towards the main peak. When the
<> Fermi energy reaches the LO-phonon energy, the phonon replica
<> and the main peak merge into one.
<> KP: PHONON INTERACTION, HETEROSTRUCTURES, SCATTERING, MODEL
<>
<> (58) TI: POLAR OPTIC PHONON-SCATTERING LIMITED-MOBILITY IN NARROW
<> QUANTUM-WELLS
<> AU: NAG_BR, MUKHOPADHYAY_S
<> NA: UNIV CALCUTTA,SISIR MITRA BHABAN,92 ACHARYA PRAFULLA CHANDRA
<> RD,CALCUTTA 700009,W BENGAL,INDIA
<> JN: JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS SHORT
<> NOTES & REVIEW PAPERS, 1992, Vol.31, No.10, pp.3287-3291
<> IS: 0021-4922
<> AB: Polar optic phonon scattering and mobility limited by such
<> scattering are discussed for quantum wells with widths ranging
<> between 10 nm and 2 nm. Numerical results are given for the
<> InP/Ga0.4.7In0.53As/InP system for both the bulk-mode and the
<> confined-mode models. Mobilities are found to be close to those
<> given by the infinite-barrier, parabolic-band, bulk-mode model
<> even when all the refinements of bulk-mode theory are taken
<> into account or the analysis is made by using the confined-mode
<> theory.
<> KP: ELECTRON, HETEROSTRUCTURES, SEMICONDUCTORS
<> WA: ELECTRON MOBILITY, POLAR OPTIC PHONON, QUANTUM WELL
<>
<> (59) TI: THE EFFECT OF ELECTRIC-FIELD ON INTRASUBBAND AND INTERSUBBAND
<> TRANSITIONS VIA INTERFACE PHONONS IN GAAS-ALAS QUANTUM-WELLS
<> AU: WEBER_G
<> NA: UNIV FED MINAS GERAIS,INST CIENCIAS EXATAS,DEPT FIS,CAIXA
<> POSTAL 702,BR-30161-970 BELO HORIZON,MG,BRAZIL
<> JN: JOURNAL OF PHYSICS-CONDENSED MATTER, 1992, Vol.4, No.49,
<> pp.9831-9842
<> IS: 0953-8984
<> AB: We calculate the scattering rates for intrasubband and
<> intersubband transitions in GaAs-AlAs quantum wells due to
<> interface phonons with an applied longitudinal electric field.
<> The electron-interface-phonon (Frohlich) Hamiltonian used is
<> that obtained from the Fuchs-Kliewer slab model, and the
<> electron envelope wavefunction under the influence of an
<> electric field parallel to the growth direction is obtained by
<> a variational method. The usual selection rules for these
<> transitions break down and the scattering rates are found to
<> increase significantly when an electric field is applied. These
<> scattering rates may even become the dominant scattering
<> mechanism for large quantum wells and sufficiently high fields.
<> We observe also that this change in scattering rates has an
<> important dependence on the interface-phonon dispersion.
<> KP: RESONANT RAMAN-SCATTERING, DOUBLE HETEROSTRUCTURES, FROHLICH
<> INTERACTION, VIBRATIONAL-MODES, SUPERLATTICES, RESOLUTION,
<> RELAXATION, RATES, SLAB
<>
<> (60) TI: THE INTERACTION OF INTERFACE OPTICAL PHONONS WITH AN ELECTRON
<> IN AN ASYMMETRIC QUANTUM-WELL
<> AU: XI_XL
<> NA: NEIMENGGU UNIV,DEPT PHYS,SOLID STATE PHYS LAB,NEIMENGGU
<> 010021,PEOPLES R CHINA
<> CHINESE CTR ADV SCI & TECHNOL,WORLD LAB,BEIJING 100080,PEOPLES
<> R CHINA
<> JN: JOURNAL OF PHYSICS-CONDENSED MATTER, 1992, Vol.4, No.49,
<> pp.9769-9778
<> IS: 0953-8984
<> AB: Long-wavelength optical modes of lattice vibrations are studied
<> and a Frohlich-like Hamiltonian of the interaction between an
<> electron and the interface optical phonons is derived.
<> Interesting properties of the interface optical modes and their
<> coupling with electrons are found. The numerical results for
<> the dispersion relations, eigenvectors and coupling functions
<> of the interface optical phonons in several practical systems
<> are obtained and discussed. It is shown that the interface
<> optical modes should be taken into consideration in theoretical
<> investigations of electron-phonon scattering in
<> heterostructures.
<> KP: DOUBLE HETEROSTRUCTURES, HETEROJUNCTIONS, FREQUENCY, GAAS,
<> GA0.47IN0.53AS, POLARIZABILITY, SYSTEMS, SINGLE
<>
<> (61) TI: TUNNELING ESCAPE OF ELECTRONS FROM A DOUBLE-BARRIER STRUCTURE
<> AU: ZOU_NZ, RAMMER_J, CHAO_KA
<> NA: UNIV TRONDHEIM,NORWEGIAN INST TECHNOL,DEPT PHYS & MATH,DIV
<> PHYS,N-7034 TRONDHEIM,NORWAY
<> JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1992, Vol.46, No.24,
<> pp.15912-15921
<> IS: 0163-1829
<> AB: The lifetime tau(e) of an electron occupying the quasibound
<> state in an AlxGa1-xAs/GaAs double-barrier structure has been
<> calculated with both the tunneling Hamiltonian approach and the
<> complex eigenvalue method. It is found that tau(e) is dominated
<> by the barrier width, but is insensitive to the well width and
<> the bias. We have also investigated the effect of the electron-
<> LO-phonon interaction on the dynamics of the electron in the
<> quasibound state. Under the condition of perfect interfaces,
<> the tunneling mechanism does not depend on the momentum
<> component parallel to the interfaces. As a consequence, the
<> total probability of the electron remaining in the quantum well
<> obeys a sum rule, and the tunneling escape rate is the same for
<> both the coherent and the incoherent tunneling process. The
<> estimated time scale of the electron-LO-phonon scattering is
<> comparable to tau(e) for typical double-barrier structures used
<> in high-speed electronic devices. Our theoretical curve of
<> tau(e) vs the barrier width reproduces the characteristic
<> features of the experimental results, where the observed
<> temperature dependence is due to the electron-hole
<> recombination, which has been ignored in our theory.
<> KP: INELASTIC-SCATTERING, PHONON INTERACTION, QUANTUM WELLS,
<> HETEROSTRUCTURES, MODEL, DEPENDENCE, FIELD
<>
<> (62) TI: INTERFACE-PHONON-ASSISTED GAMMA-X TRANSITIONS IN SHORT-PERIOD
<> SUPERLATTICES
<> AU: DUTTA_M, STROSCIO_MA
<> NA: USA,RES LAB,ELECTR & POWER SOURCES DIRECTORATE,FT
<> MONMOUTH,NJ,07703
<> USA,RES OFF,RES TRIANGLE PK,NC,27709
<> JN: JOURNAL OF APPLIED PHYSICS, 1993, Vol.73, No.4, pp.1693-1701
<> IS: 0021-8979
<> AB: The dielectric continuum model of longitudinal-optical phonons
<> in polar semiconductors is used to define the role of interface
<> longitudinal-optical phonons- in affecting phonon-assisted
<> GAMMA-x transitions in GaAs-AlAs and GaAs-GaP superlattices. In
<> particular, the dielectric continuum model for interface
<> optical phonons is used in conjunction with a Kronig-Penney
<> model of the superlattice electronic properties for two
<> purposes: to specify superlattice parameters where interface-
<> phonon-assisted GAMMA-X transitions are expected and to
<> estimate relative transition probability amplitudes for
<> interface-phonon-assisted GAMMA-x transitions in selected
<> short-period superlattices.
<> KP: SEMICONDUCTOR HETEROINTERFACES, MINIBAND STRUCTURE, ENVELOPE
<> FUNCTIONS, QUANTUM-WELLS, HETEROSTRUCTURES, CONNECTION
<>
<> (63) TI: PHONONS IN THIN GAAS QUANTUM WIRES
<> AU: ROSSI_F, ROTA_L, BUNGARO_C, LUGLI_P, MOLINARI_E
<> NA: UNIV MODENA,DIPARTIMENTO FIS,VIA CAMPI 213-A,I-41100
<> MODENA,ITALY
<> UNIV ROMA TOR VERGATA,DIPARTIMENTO INGN ELETTRON,I-00173
<> ROME,ITALY
<> CNR,IST OM CORBINO,I-00189 ROME,ITALY
<> JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1993, Vol.47, No.3,
<> pp.1695-1698
<> IS: 0163-1829
<> DT: Note
<> AB: Phonon frequencies and potentials for an array of thin
<> rectangular GaAs wires embedded in AlAs are calculated within a
<> microscopic scheme. The confined and interface character of
<> optical modes are clearly evident from their dispersion and
<> from the spatial profiles. Our results allow us to conclude
<> that macroscopic models based on the dielectric continuum
<> scheme are adequate to describe confined phonon profiles at
<> wave vectors relevant to el-ph scattering, in contrast with
<> approaches based on mechanical boundary conditions, which yield
<> modes with the wrong symmetry sequence. The implications for
<> electron-phonon scattering rates are discussed.
<> KP: SCATTERING, MODES
<>
<> (64) TI: ELECTRON-TUNNELING IN GAAS/ALGAAS/GAAS SINGLE-BARRIER
<> HETEROJUNCTION DIODES - ELECTRON PHONON INTERACTION EFFECTS
<> AU: MORI_N, HAMAGUCHI_C
<> NA: OSAKA UNIV,DEPT ELECTR ENGN,2-1 YAMADA OKA,SUITA,OSAKA
<> 565,JAPAN
<> JN: SEMICONDUCTOR SCIENCE AND TECHNOLOGY, 1993, Vol.8, No.2,
<> pp.197-205
<> IS: 0268-1242
<> AB: The tunnelling current, the conductance and the second
<> derivative of the current through single-barrier heterojunction
<> diodes of GaAs/Al0.5Ga0.5As/GaAs are calculated including
<> electron-phonon interaction in the electrodes. The effects of
<> interface phonons are taken into account by using the
<> dielectric continuum model. The conductance decreases when the
<> applied voltage is greater than the value corresponding to the
<> optical phonon energy. The role of the interface phonons in the
<> decrease is studied, and ft is found that the symmetric
<> interface mode originating in GaAs electrodes plays the most
<> significant role. The magnitude of the decrease and the onset
<> are also discussed.
<> KP: DOUBLE HETEROSTRUCTURES, SEMICONDUCTOR SUPERLATTICES, OPTICAL
<> PHONONS, POLARIZABILITY
<>
<> (65) TI: ROLE OF INTERFACE OPTICAL PHONONS IN COOLING HOT CARRIERS IN
<> GAAS-ALAS QUANTUM-WELLS
<> AU: OBERLI_DY, BOHM_G, WEIMANN_G
<> NA: TECH UNIV MUNICH,WALTER SCHOTTKY INST,W-8046 GARCHING,GERMANY
<> JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1993, Vol.47, No.12,
<> pp.7630-7633
<> IS: 0163-1829
<> DT: Note
<> AB: We present an experimental study of the nonequilibrium phonon
<> population generated by the relaxation of hot carriers
<> photoexcited in GaAs-AlAs quantum wells. The optical phonon
<> population is measured by anti-Stokes Raman scattering
<> performed in the plane of the layers. The measured occupation
<> numbers suggest that interface phonon modes contribute
<> significantly to the relaxation dynamics over the lifetime of
<> an electron-hole pair. These results are explained on the basis
<> of the interplay between emission and reabsorption of hot
<> phonons, which leads to a large population of interface phonons
<> under steady-state conditions.
<> KP: LO PHONONS, SUPERLATTICES, SCATTERING, MODES
<>
<> (66) TI: ELECTRON-PHONON INTERACTION IN GAAS/ALAS SUPERLATTICES
<> AU: TSUCHIYA_T, ANDO_T
<> NA: UNIV TOKYO,INST SOLID STATE PHYS,7-22-1 ROPPONGI,MINATO
<> KU,TOKYO 106,JAPAN
<> JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1993, Vol.47, No.12,
<> pp.7240-7252
<> IS: 0163-1829
<> AB: Scattering rates of an electron in GaAs/AlAs superlattices are
<> calculated in an envelope-function approximation which
<> reproduces long-wavelength optical phonons almost completely.
<> The polaron damping rate increases with decreasing layer-
<> thickness at 300 K, while this dependence is smaller at 77 K.
<> Intersubband relaxation rates decrease almost linearly as the
<> layer thickness decreases. The results obtained in the
<> dielectric continuum model agree quite well with those in the
<> envelope-function approximation and even the bulk-phonon model
<> explains the layer-thickness dependence reasonably well. This
<> approximate model independence is explained by the completeness
<> of the lattice vibration.
<> KP: SEMICONDUCTOR QUANTUM-WELLS, POLAR-OPTICAL PHONONS, COLLECTIVE
<> EXCITATIONS, RAMAN-SCATTERING, GAAS-ALAS, DOUBLE
<> HETEROSTRUCTURES, ALTERNATING MONOLAYERS, FROHLICH INTERACTION,
<> CYCLOTRON-RESONANCE, INTERFACE
<>
<> (67) TI: FAR-INFRARED SPECTROSCOPY OF PHONONS AND PLASMONS IN
<> SEMICONDUCTOR SUPERLATTICES
<> AU: DUMELOW_T, PARKER_TJ, SMITH_SRP, TILLEY_DR
<> NA: UNIV ESSEX,DEPT PHYS,COLCHESTER CO4 3SQ,ESSEX,ENGLAND
<> JN: SURFACE SCIENCE REPORTS, 1993, Vol.17, No.3, pp.151-212
<> IS: 0167-5729
<> DT: Review
<> AB: Experimental far-infrared spectra of semiconductor
<> superlattices and the related theory are reviewed. An account
<> is given of Fourier-transform spectroscopy in various forms. In
<> discussing superlattice spectra, a distinction is made between
<> long- and short-period superlattices. In the former the
<> constituent layers are many monolayers thick and can be
<> described as slabs of the corresponding bulk material. A fairly
<> simple account of the far-infrared optics can be based on this
<> description, which is usually applied by treating the
<> superlattice as a uniaxial effective medium in which the
<> dielectric-tensor components are given by averages over the
<> dielectric constants of the layer materials. Examples of
<> spectra are shown for all the main experimental techniques. In
<> short-period superlattices the effect of confinement on the
<> dielectric function must be included; this review concentrates
<> on the effect on phonon modes. Experimental measurements of
<> confined-mode frequencies show significant shifts from values
<> predicted by theories that assume perfect interfaces. This
<> indicates that the effect of interface roughness must be
<> included into phonon-confinement models. It is shown how this
<> can be incorporated into a 1D lattice-dynamic model which leads
<> to a generalised effective-medium description. Comparison with
<> experimental results is presented. Possible future developments
<> are discussed in a final section.
<> KP: ATTENUATED-TOTAL-REFLECTION, GAAS-ALAS SUPERLATTICES, HGTE-CDTE
<> SUPERLATTICE, WAVELENGTH OPTICAL PHONONS, METAL-INSULATOR
<> SUPERLATTICES, STRAINED-LAYER SUPERLATTICES, QUANTUM-WELL
<> STRUCTURES, ELECTRON-ENERGY-LOSS, VALENCE-BAND OFFSET, SEMI-
<> INFINITE
<>
<> (68) TI: INTERFACE OPTICAL PHONON MODE-COUPLING IN GAAS/ALAS QUANTUM-
<> WELLS AT HIGH MAGNETIC-FIELDS
<> AU: HAI_GQ, PEETERS_FM, DEVREESE_JT
<> NA: UNIV ANTWERP,DEPT PHYS,UNIV SPLEIN 1,B-2610 ANTWERP,BELGIUM
<> JN: PHYSICA B, 1993, Vol.184, No.1-4, pp.289-292
<> IS: 0921-4526
<> AB: The coupling of electrons to interface and slab optical optical
<> phonon modes is studied in the presence of a high magnetic
<> field in a GaAs/AlAs quantum well. The position of the Landau
<> levels and the magneto-optical absorption spectrum for
<> cyclotron resonance are calculated. We find that in narrow
<> GaAs/AlAs quantum wells a substantial coupling of the electron
<> to the interface phonons shows up near the LO- and TO-phonon
<> modes of GaAs and AlAs.
<> KP: DOUBLE HETEROSTRUCTURES, 3-DIMENSIONAL POLARONS, CYCLOTRON-
<> RESONANCE, ENERGY
<>
<> (69) TI: RATE-EQUATIONS FROM THE KELDYSH FORMALISM APPLIED TO THE PHONON
<> PEAK IN RESONANT-TUNNELING DIODES
<> AU: LAKE_R, KLIMECK_G, DATTA_S
<> NA: PURDUE UNIV,SCH ELECT ENGN,W LAFAYETTE,IN,47907
<> JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1993, Vol.47, No.11,
<> pp.6427-6438
<> IS: 0163-1829
<> AB: Starting from the Keldysh formalism, general analytical
<> expressions are derived for the current and the occupation of
<> the well in the presence of inelastic scattering, both at the
<> main peak and at the phonon peak. These expressions are then
<> evaluated from a continuous coordinate representation of a
<> double-barrier potential profile and also from a tight-binding
<> model of a weakly coupled central site. The resulting
<> expressions are similar, and the analytical expressions derived
<> from the continuous coordinate representation compare well with
<> the results obtained from numerical simulations. The analytical
<> expressions and the numerical results show that unlike the main
<> peak, the phonon peak is normally independent of the collector
<> transmissivity. But with very opaque collector barriers, the
<> resonant level fills up and the current decreases because the
<> inelastic scattering is suppressed by the exclusion principle.
<> An alternative but equivalent point of view is that the
<> effective coupling GAMMA(E)' between the incident energy in the
<> emitter and the resonant energy in the well is g'GAMMA(E) Where
<> g' is the effective phonon coupling constant and GAMMA(E) is
<> HBAR times the tunneling rate through the emitter barrier. The
<> total low-temperature inelastic current at the phonon-peak bias
<> is (2e/HBAR)GAMMA(E)'GAMMA(C)/(GAMMA(E)' + GAMMA(C)). Since g'
<> < 1, the effective coupling GAMMA(E)' determines the current
<> until GAMMA(C) is reduced to approximately GAMMA(E)'. The
<> ''backflow'' correction to the current due to absorption of
<> phonons is derived, interpreted, and limiting cases discussed.
<> The approach described here could be applied to other problems
<> involving resonant tunneling in the presence of inelastic
<> scattering.
<> KP: DOUBLE-BARRIER HETEROSTRUCTURES, INELASTIC-SCATTERING,
<> INTRINSIC BISTABILITY, QUANTUM TRANSPORT, KINETIC-EQUATION,
<> MAGNETOPOLARONS, CONDUCTANCE, EMISSION, DEVICES, FIELDS
<>
<> (70) TI: REDUCTION OF INTERFACE PHONON MODES USING METAL-SEMICONDUCTOR
<> HETEROSTRUCTURES
<> AU: BHATT_AR, KIM_KW, STROSCIO_MA, LAFRATE_GJ, DUTTA_M, GRUBIN_HL,
<> HAQUE_R, ZHU_XT
<> NA: N CAROLINA STATE UNIV,DEPT ELECT & COMP ENGN,RALEIGH,NC,27695
<> USA,RES OFF,RES TRIANGLE PK,NC,27709
<> USA,RES LAB,ELECTR & POWER SOURCES DIRECTORATE,FT
<> MONMOUTH,NJ,07703
<> SCI RES ASSOCIATES INC,GLASTONBURY,CT,06033
<> DUKE UNIV,DEPT PHYS,DURHAM,NC,27706
<> MOTOROLA INC,PHOENIX CORP RES LABS,TEMPE,AZ,85284
<> JN: JOURNAL OF APPLIED PHYSICS, 1993, Vol.73, No.5, pp.2338-2342
<> IS: 0021-8979
<> AB: Based on a simplified analysis of perfectly conducting metals,
<> it has been suggested qualitatively that establishing metal-
<> semiconductor interfaces at the heterojunctions of polar
<> semiconductor quantum wells introduces a set of boundary
<> conditions that dramatically reduces or eliminates unwanted
<> carrier energy loss caused by interactions with interface
<> longitudinal-optical (LO) phonon modes. In this article, it is
<> theoretically demonstrated that comparable reductions in LO
<> phonon scattering strengths may be achieved for metal-
<> semiconductor structures with metal having realistic
<> conductivities and Thomas-Fermi screening lengths.
<> KP: MOLECULAR-BEAM EPITAXY, OHMIC CONTACTS, QUANTUM WIRE, GROWTH,
<> SUPERLATTICES, SCATTERING, TRANSISTOR, LAYERS, SYSTEM, HEIGHT
<>
<> (71) TI: POLARON-CYCLOTRON-RESONANCE SPECTRUM RESULTING FROM INTERFACE-
<> PHONON AND SLAB-PHONON MODES IN A GAAS/ALAS QUANTUM-WELL
<> AU: HAI_GQ, PEETERS_FM, DEVREESE_JT
<> NA: UNIV ANTWERP,DEPT NAT KUNDE,UNIV PLEIN 1,B-2610 ANTWERP,BELGIUM
<> EINDHOVEN UNIV TECHNOL,5600 MB EINDHOVEN,NETHERLANDS
<> RUCA,B-2020 ANTWERP,BELGIUM
<> JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1993, Vol.47, No.16,
<> pp.10358-10374
<> IS: 0163-1829
<> AB: The effects of interface optical-phonon and confined slab LO-
<> phonon modes on the polaron cyclotron-resonance frequency are
<> investigated for a GaAs/AlAs quantum well. Using degenerate
<> second-order perturbation theory, the polaron Landau levels are
<> calculated and the polaron resonant region is investigated. In
<> order to know the relative importance of the different resonant
<> frequencies we present a full calculation of the magneto-
<> optical absorption spectrum. At a fixed magnetic field we found
<> four different peaks in the absorption spectrum. The relative
<> oscillator strength of the different peaks changes with
<> increasing magnetic field. For comparative purposes, the
<> polaron Landau levels and cyclotron mass are also calculated
<> using only the bulk LO-phonon modes. The influence of the
<> finiteness of the confinement potential is investigated. We
<> found that the interface-phonon modes influence the
<> magnetopolaron resonance considerably near the optical-phonon
<> frequencies for narrow wells. In the limit of zero magnetic
<> field we recover our previous results and in the case of an
<> infinite-barrier quantum well we are able to recover the
<> results for a two- and three-dimensional system.
<> KP: MAGNETIC-FIELD, ELECTRONIC POLARIZABILITY, DOUBLE
<> HETEROSTRUCTURES, 3-DIMENSIONAL POLARONS, STATISTICAL
<> PROPERTIES, PHASE-TRANSITION, 2 DIMENSIONS, GAAS, ENERGY,
<> MAGNETOPOLARON
<>
<> (72) TI: 2-DIMENSIONAL GALVANOMAGNETIC TRANSPORT IN GAAS QUANTUM-WELLS
<> AU: GHOSH_PK, CHATTOPADHYAY_D, GHOSAL_A, MULIMANI_BG
<> NA: INST RADIOPHYS & ELECTR,92 ACHARYA PRAFULLA CHANDRA RD,CALCUTTA
<> 700009,W BENGAL,INDIA
<> KARNATAK UNIV,DEPT PHYS,DHARWAR 580003,KARNATAKA,INDIA
<> JN: PHYSICA STATUS SOLIDI B-BASIC RESEARCH, 1993, Vol.176, No.2,
<> pp.451-457
<> IS: 0370-1972
<> AB: Hall mobility, Hall ratio, and magnetoresistance coefficient of
<> the electrons two-dimensionally itinerant in a square quantum
<> well of GaAs are calculated in the regime of dominant lattice
<> scattering. A numerical iterative solution of the Boltzmann
<> equation is used considering Fermi-Dirac statistics. The
<> variation of the galvanomagnetic coefficients is studied with
<> temperature, 2D carrier concentration, channel width, and
<> magnetic field in the classical region.
<> KP: SCATTERING MOBILITY, PHONON INTERACTION, HETEROSTRUCTURES
<>
<> (73) TI: STUDY OF ELECTRON-PHONON INTERACTION IN QUANTUM-WELLS USING
<> OPTICALLY-EXCITED NONEQUILIBRIUM POPULATION OF PHONONS
<> AU: RUF_T, WALD_K, YU_PY, TSEN_KT, MORKOC_H, CHAN_KT
<> NA: UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA,94720
<> LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA,94720
<> ARIZONA STATE UNIV,DEPT PHYS,TEMPE,AZ,85287
<> UNIV ILLINOIS,COORDINATED SCI LAB,URBANA,IL,61801
<> HEWLETT PACKARD CO,DIV MICROWAVE TECHNOL,SANTA ROSA,CA,95403
<> JN: SUPERLATTICES AND MICROSTRUCTURES, 1993, Vol.13, No.2, pp.203-
<> 208
<> IS: 0749-6036
<> KP: GAAS-ALAS SUPERLATTICES, RAMAN-SCATTERING, CONFINED LO, MODES,
<> HETEROSTRUCTURES
<>
<> (74) TI: DIRECT MEASUREMENTS OF ELECTRON-OPTICAL PHOTON SCATTERING RATES
<> IN ULTRATHIN GAAS-ALAS MULTIPLE-QUANTUM-WELL STRUCTURES
<> AU: TSEN_KT, JOSHI_R, MORKOC_H
<> NA: ARIZONA STATE UNIV,DEPT PHYS & ASTRON,TEMPE,AZ,85287
<> OLD DOMINION UNIV,DEPT ELECTR & COMP ENGN,NORFOLK,VA,23529
<> UNIV ILLINOIS,COORDINATED SCI LAB,URBANA,IL,61801
<> JN: APPLIED PHYSICS LETTERS, 1993, Vol.62, No.17, pp.2075-2077
<> IS: 0003-6951
<> AB: Electron-optical phonon scattering rates in ultrathin GaAs-AlAs
<> multiple quantum well structures have been directly measured by
<> using time-resolved Raman spectroscopy on a subpicosecond
<> timescale. We have found that when the GaAs well width
<> increases from 20 to 60 angstrom, electron-AlAs-like-optical
<> phonon scattering rate decreases by a factor of about 3. The
<> experimental results are explained with theoretical
<> calculations of electron-optical phonon interactions recently
<> carried out by K. Huang and B. Zhu [Phys. Rev. B 38, 13377
<> (1988)].
<> KP: CONFINED LO, PHONON INTERACTION, SUPERLATTICES, RAMAN,
<> SPECTROSCOPY
<>
<> (75) TI: CYCLOTRON EFFECTIVE MASS OF A POLARON IN A SINGLE QUANTUM-WELL
<> AU: ZHAO_FQ, WANG_X, LIANG_XX
<> NA: NEIMENGGU EDUC COLL,DEPT PHYS,HOHHOT 010010,PEOPLES R CHINA
<> NEIMENGGU UNIV,DEPT PHYS,SOLID STATE PHYS LAB,HOHHOT
<> 010021,PEOPLES R CHINA
<> CCAST,WORLD LAB,BEIJING 100080,PEOPLES R CHINA
<> JN: PHYSICS LETTERS A, 1993, Vol.175, No.3-4, pp.225-232
<> IS: 0375-9601
<> AB: Magnetopolarons in a quantum well are studied in the case of a
<> weak external magnetic field. Both the bulk-like LO and the
<> interface optical (IO) phonon modes are included in the
<> calculation of the polaron energy levels. The numerical results
<> of the cyclotron effective mass (m*) in a GaAs/AlGaAs quantum
<> well are given and discussed. An expected dependence of the
<> cyclotron mass on the well width is obtained. A correction of
<> the nonparabolicity of the conduction band is considered and
<> results in agreement with recent experiments are given.
<> KP: PHONON INTERACTION, RESONANCE, HETEROJUNCTIONS, ELECTRONS,
<> MAGNETOPOLARON
<>
<> (76) TI: NORMAL AND HOT ELECTRO-PHONON RESONANCE EFFECT IN A QUASI-2-
<> DIMENSIONAL SEMICONDUCTOR SYSTEM
<> AU: XU_W, PEETERS_FM, DEVREESE_JT
<> NA: UNIV INSTELLING ANTWERP,DEPT NATUURKUNDE,UNIV SPL 1,B-2610
<> WILRIJK,BELGIUM
<> RUCA,B-2020 ANTWERP,BELGIUM
<> TECH UNIV EINDHOVEN,5600 EINDHOVEN,NETHERLANDS
<> JN: JOURNAL OF PHYSICS-CONDENSED MATTER, 1993, Vol.5, No.15,
<> pp.2307-2320
<> IS: 0953-8984
<> AB: The electro-phonon resonance effect is a consequence of a
<> resonant interaction between two electric subbands mediated by
<> an optical phonon. It occurs in a quasi-two-dimensional
<> electron system each time the energy difference between two
<> electric subbands equals the energy of a Lo phonon. We study
<> the influence of this effect on the electron mobility by using
<> the momentum balance equation. The temperature and electron
<> density dependences of the resonances are studied in the linear
<> and non-linear response regimes.
<> KP: INTERSUBBAND POPULATION-INVERSION, QUANTUM WIRE STRUCTURES,
<> FORCE-BALANCE THEORY, MAGNETOPHONON-RESONANCE, TRANSPORT,
<> SCATTERING, FIELD, HETEROSTRUCTURES, HETEROJUNCTIONS,
<> RESISTIVITY
<>
<> (77) TI: INTERFACE OPTICAL-PHONON MODES IN A 4-LAYER HETEROSTRUCTURE OF
<> POLAR CRYSTALS
<> AU: SHI_JJ, SHANGGUAN_LX, PAN_SH
<> NA: ACAD SINICA,INST PHYS,POB 603,BEIJING 100080,PEOPLES R CHINA
<> HENAN NORMAL UNIV,DEPT PHYS,XINXIANG 453002,HENAN,PEOPLES R
<> CHINA
<> HENAN NORMAL UNIV,DEPT MATH,XINXIANG 453002,HENAN,PEOPLES R
<> CHINA
<> CHINA CTR ADV SCI & TECHNOL,WORLD LAB,BEIJING 100080,PEOPLES R
<> CHINA
<> JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1993, Vol.47, No.20,
<> pp.13471-13477
<> IS: 0163-1829
<> AB: The equations of motion for the p-polarization field in a four-
<> layer heterostructure (FLHS) of polar crystals are solved
<> exactly for the interface optical-phonon modes. The
<> eigenvectors and the interface charge densities are obtained
<> explicitly. The dispersion relations and their plots for a FLHS
<> and its special cases, an asymmetric trilayer heterostructure
<> (asymmetric single quantum well) and a step quantum well, are
<> given and discussed. We find that there are six (not eight)
<> frequency solutions for the interface optical-phonon modes in a
<> FLHS and that, in the long-wavelength limit, the longitudinal
<> and transverse modes in the two side materials 1 and 4 with
<> frequencies (omega(L1), omega(L4), omega(T1), and omega(T4))
<> are forbidden (the four-layer structure comprises layers 1-4);
<> two frequency solutions are obtained in their stead. These
<> results are due to the asymmetry of the structure. Moreover, we
<> also find that the situation in an asymmetric trilayer
<> heterostructure is similar to that of a FLHS. This work can be
<> regarded as a generalization of the formalism of Chen, Lin, and
<> George [Phys. Rev. B 41, 1435 (1990)].
<> KP: SEMICONDUCTOR QUANTUM-WELLS, GAAS-ALAS SUPERLATTICES, CONFINED
<> LO, ELECTRONIC POLARIZABILITY, GAAS/ALAS SUPERLATTICES, RAMAN-
<> SCATTERING, SLAB
<>
<> (78) TI: TUNNELING MEASUREMENTS OF SYMMETRICAL-INTERFACE PHONONS IN
<> GAAS/ALAS DOUBLE-BARRIER STRUCTURES
<> AU: TURLEY_PJ, WALLIS_CR, TEITSWORTH_SW, LI_W, BHATTACHARYA_PK
<> NA: DUKE UNIV,DEPT PHYS,BOX 90305,DURHAM,NC,27708
<> UNIV MICHIGAN,DEPT ELECT ENGN & COMP SCI,ANN ARBOR,MI,48109
<> JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1993, Vol.47, No.19,
<> pp.12640-12648
<> IS: 0163-1829
<> AB: In this paper we report the results of extensive
<> magnetotransport experiments on asymmetric GaAs/AlAs double-
<> barrier structures that were specifically designed to possess
<> large phonon-assisted tunneling currents. We find quantitative
<> agreement between measured valley currents at liquid-helium
<> temperature and calculations that include the effects of phonon
<> localization using the dielectric-continuum model. The results
<> demonstrate that (1) a major part of the valley current in
<> these structures is due to phonon-assisted tunneling, and (2)
<> symmetric-interface phonons and confined phonons in the GaAs
<> well are the most important in phonon-assisted tunneling
<> processes. Charge buildup in the GaAs well is found to shift
<> current-voltage curves to higher voltages and to distort
<> magnetic field versus applied voltage diagrams.
<> KP: ELASTIC-SCATTERING, CHARGE BUILDUP, VALLEY CURRENT,
<> HETEROSTRUCTURES, SUPERLATTICES, MAGNETOPOLARONS, EMISSION,
<> DIODES, MODES
<>
<> (79) TI: PHONON-ASSISTED TRANSPORT IN DOUBLE-BARRIER RESONANT-TUNNELING
<> STRUCTURES
<> AU: GREIN_CH, RUNGE_E, EHRENREICH_H
<> NA: HARVARD UNIV,DIV APPL SCI,CAMBRIDGE,MA,02138
<> HARVARD UNIV,DEPT PHYS,CAMBRIDGE,MA,02138
<> JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1993, Vol.47, No.19,
<> pp.12590-12597
<> IS: 0163-1829
<> AB: The dc current in a biased double-barrier resonant-tunneling
<> structure is calculated using a nonequilibrium Green's-function
<> formalism. Realistic models involving well, barrier, and
<> interface modes are employed to evaluate the phonon-assisted
<> components of the current. The calculated dc current agrees
<> well with experimental data for GaAs/AlxGa1-xAs resonant-
<> tunneling structure. The observed phonon-replica peak in the I-
<> V characteristics is attributed to the emission of GaAs-
<> confined modes in the well and AlAs-like symmetric interface
<> modes. The effect of the nonequilibrium well-occupation
<> function is shown to be small. For the InxAl1-xAs/InxGa1-xAs
<> resonant-tunneling structure, phonon scattering becomes
<> comparable to alloy-well scattering at about 200 K.
<> KP: SEMICONDUCTOR QUANTUM-WELLS, CONFINED LO, DOUBLE
<> HETEROSTRUCTURES, INELASTIC-SCATTERING, ELECTRON-SCATTERING,
<> RAMAN-SCATTERING, POLAR PHONONS, SUPERLATTICES, SPECTROSCOPY,
<> EMISSION
<>
<> (80) TI: SIZE DEPENDENCE OF PHONON MODES IN A RECTANGULAR QUANTUM DOT
<> AU: ZHOU_HY, GU_SW
<> NA: CCAST,WORLD LAB,BEIJING 100080,PEOPLES R CHINA
<> JIAO TONG UNIV,DEPT APPL PHYS,SHANGHAI 200030,PEOPLES R CHINA
<> JN: SOLID STATE COMMUNICATIONS, 1993, Vol.86, No.6, pp.403-406
<> IS: 0038-1098
<> AB: The polar surface-optical (SO) phonon modes and their
<> dispersion relations in a rectangular quantum dot are derived
<> within the dielectric continuum approximation, which is
<> expected to be valid for vibrations with wavelengths
<> considerably longer than the interatomic spacing.
<> KP: DOUBLE HETEROSTRUCTURES, INTERFACE PHONONS, WELL-WIRE, CRYSTALS,
<> SUPERLATTICES, CONFINEMENT, SURFACE, ENERGY
<>
<> (81) TI: TRANSIENT AND STEADY-STATE ANALYSIS OF ELECTRON-TRANSPORT IN
<> ONE-DIMENSIONAL COUPLED QUANTUM-BOX STRUCTURES
<> AU: NOGUCHI_H, LEBURTON_JP, SAKAKI_H
<> NA: UNIV TOKYO,ADV SCI & TECHNOL RES CTR,4-6-1 KOMABA,MEGURO
<> KU,TOKYO 153,JAPAN
<> UNIV TOKYO,INST IND SCI,MINATO KU,TOKYO 106,JAPAN
<> UNIV ILLINOIS,BECKMAN INST ADV SCI & TECHNOL,URBANA,IL,61801
<> JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1993, Vol.47, No.23,
<> pp.15593-15600
<> IS: 0163-1829
<> AB: We investigate electron transport in one-dimensional coupled
<> quantum-box (1D-CQB) structures at room temperature by using an
<> iterative technique for solving the time-dependent Boltzmann
<> equation. The scattering rates in the mini-Brillouin zone are
<> characterized by several large peaks reflecting the
<> singularities of the 1D density of states and the features of
<> the miniband structure. As a result of Bragg reflection, the
<> momentum distribution function deviates significantly from a
<> displaced Maxwellian, with carrier accumulation at the miniband
<> edges. Under the condition of suppression of optic-phonon
<> scattering, the time evolution of the distribution function,
<> and the electron velocity under high electric field undergo
<> damped Bloch oscillations with a period of a few picoseconds.
<> In the steady-state analysis, we found that the carrier
<> mobility is a strong function of the structure confinement and
<> periodicity parameters.
<> KP: OPTICAL-PHONON-SCATTERING, CONFINED LO PHONONS, WIRE STRUCTURES,
<> SEMICONDUCTORS, SUPERLATTICES, WELLS
<>
<> (82) TI: INTERACTION HAMILTONIAN BETWEEN AN ELECTRON AND POLAR SURFACE
<> VIBRATIONS IN A SYMMETRICAL 3-LAYER STRUCTURE
<> AU: POKATILOV_EP, FOMIN_VM, SEMENOVSKAYA_NN, BERIL_SI
<> NA: MOLDAVIAN STATE UNIV,DEPT THEORET PHYS,PHYS MULTILAYER STRUCT
<> LAB,STR MATEEVICI 60,KISHINEV 277014,MOLDOVA
<> UNIV TIRASPOL,DEPT PHYS,TIRASPOL 278000,MOLDOVA
<> JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1993, Vol.47, No.24,
<> pp.16597-16600
<> IS: 0163-1829
<> DT: Note
<> AB: The Hamiltonian of the interaction between an electron and
<> surface vibrations for a three-layer symmetrical structure is
<> obtained. In the limiting case of infinite outer-layer
<> thickness, the known results by Mori and Ando are reproduced.
<> KP: PHONON INTERACTION
<>
<> (83) TI: PHONON REPLICA IN THE IV CHARACTERISTICS OF A GAAS/ALGAAS
<> DOUBLE-BARRIER STRUCTURE
<> AU: ZOU_NZ, RAMMER_J, CHAO_KA
<> NA: UNIV TRONDHEIM,NORWEGIAN INST TECHNOL,DEPT PHYS & MATH,DIV
<> PHYS,N-7034 TRONDHEIM,NORWAY
<> JN: INTERNATIONAL JOURNAL OF MODERN PHYSICS B, 1993, Vol.7, No.19,
<> pp.3449-3460
<> IS: 0217-9792
<> AB: We have performed a detailed calculation of the I-V
<> characteristic of a GaAs/AlxGa1-xAs double barrier structure,
<> with special emphasis on the phonon replica. For commonly used
<> experimental samples (x congruent-to 0.3-0.4), the interface-
<> like phonon modes produced by alloying and localized in
<> barriers near the interfaces give the dominating contribution
<> to the phonon replica. Our calculated I-V curves for samples of
<> both symmetric and asymmetric barriers with or without
<> bistability agree extremely well with experimental
<> observations.
<> KP: RESONANT-TUNNELING STRUCTURES, INELASTIC-SCATTERING, ELASTIC-
<> SCATTERING, RAMAN-SCATTERING, HETEROSTRUCTURES, DIODES, FIELD,
<> MODEL, EMISSION, WELL
<>
<> (84) TI: PIEZOELECTRIC SCATTERING OF CARRIERS FROM CONFINED ACOUSTIC
<> MODES IN CYLINDRICAL QUANTUM WIRES
<> AU: STROSCIO_MA, KIM_KW
<> NA: USA,RES OFF,POB 12211,RES TRIANGLE PK,NC,27709
<> N CAROLINA STATE UNIV,DEPT ELECT & COMP ENGN,RALEIGH,NC,27695
<> JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1993, Vol.48, No.3,
<> pp.1936-1938
<> IS: 0163-1829
<> DT: Note
<> AB: Confined acoustic modes are derived for a free-standing
<> nanometer-scale cylindrical polar semiconductor quantum wire.
<> The piezoelectric scattering Hamiltonian is calculated for the
<> interaction of charge carriers with the lowest-order
<> azimuthally symmetric torsional modes in such nanometer-scale
<> quantum wires.
<> KP: OPTICAL-PHONON INTERACTION, HETEROSTRUCTURES
<>
<> (85) TI: A-PERPENDICULAR-TO.P VERSUS PHI FOR COUPLING ELECTRONS TO
<> INTERFACE OPTICAL PHONONS IN QUANTUM-WELLS
<> AU: BABIKER_M, CONSTANTINOU_NC, RIDLEY_BK
<> NA: UNIV ESSEX,DEPT PHYS,COLCHESTER CO4 3SQ,ESSEX,ENGLAND
<> JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1993, Vol.48, No.4,
<> pp.2236-2243
<> IS: 0163-1829
<> AB: The interface optical-phonon modes and their interaction with
<> electrons in layered semiconductor structures are considered.
<> In a canonical theory where retardation effects are retained
<> from the outset, the theory leads naturally to the quantization
<> of the free interface oscillations in the radiation gauge for
<> which the scalar potential is zero and the vector potential is
<> transverse (phi = 0, del.A = 0). The description is thus
<> entirely in terms of a transverse vector potential
<> A(perpendicular-to) which satisfies del.A(perpendicular-to) = 0
<> everywhere, except at the interfaces where, as usual, only
<> boundary conditions apply. The interaction between the two
<> subsystems (electrons and interface modes) is the well-known
<> minimal-coupling Hamiltonian which is in the form e
<> A(perpendicular-to).p/m*. The main aspects of the quantization
<> of such retarded modes are summarized. It is then shown that
<> for a double heterostructure the nonretarded vector potential
<> can be expressed in terms of the gradient of a unique field
<> operator LAMBDA which enters a unitary transformation
<> e(iLAMBDA). We demonstrate that the result of applying this
<> transformation on the total minimal-coupling Hamiltonian is the
<> unitary-equivalent Hamiltonian in which the coupling to
<> electrons is in the form ePHI. This PHI is identical to that
<> given by Mori and Ando. The matrix elements using the ePHI form
<> of coupling are then compared with those using the e
<> A(perpendicular).p/m* coupling and seen to be clearly
<> different. However, when the emission rates are evaluated using
<> the two coupling Hamiltonians, interesting and nontrivial
<> manipulations are required to prove that the same results
<> emerge for the total emission rate from any given initial
<> electronic state of the double heterostructure. The reasons for
<> the agreement of the two sets of results for first-order
<> transitions are pointed out and discussed.
<> KP: DOUBLE HETEROSTRUCTURES, FROHLICH INTERACTION, SUPERLATTICES,
<> POLARITONS
<>
<> (86) TI: THE INTERACTION BETWEEN ELECTRON AND PHONON LOCALIZED IN A
<> DOUBLE-BARRIER RESONANT-TUNNELING DIODE
<> AU: FU_Y, WILLANDER_M
<> NA: LINKOPING UNIV,DEPT PHYS & MEASUREMENT TECHNOL,S-58183
<> LINKOPING,SWEDEN
<> JN: JOURNAL OF APPLIED PHYSICS, 1993, Vol.74, No.5, pp.3264-3269
<> IS: 0021-8979
<> AB: The electron-phonon interaction (the transition probability
<> from the initial electronic state to the final state via the
<> electron-phonon interaction) is analyzed when electrons and
<> phonons are either extended or localized in a quantum system.
<> Compared with the situation of the bulk material where all wave
<> functions are extended, it is generally found that the
<> electron-phonon interaction is reduced when one state is
<> localized while it will be enhanced when more states involved
<> in the interaction process become localized. It has been shown
<> that the electron-phonon interaction is inversely proportional
<> to the well width when all the states involved are localized.
<> Special attention is then focused on the double-barrier
<> resonant tunneling diode. A simple Monte Carlo scheme is
<> developed to include the electron-phonon interaction process in
<> the quantum well between two barriers. The numerically
<> calculated I-V characteristics agrees much better with the
<> experimental spectra if the electron-phonon interaction has
<> been taken into account.
<> KP: INTRINSIC BISTABILITY, HETEROSTRUCTURES, MODEL
<>
<> (87) TI: OPTICAL MODES IN GAAS-BASED QUANTUM-WELLS
<> AU: PEREZALVAREZ_R, GARCIAMOLINER_F, VELASCO_VR, TRALLEROGINER_C
<> NA: CSIC,INST CIENCIA MAT,SERRANO 123,E-28006 MADRID,SPAIN
<> UNIV LA HABANA,DEPT FIS TEOR,HAVANA,CUBA
<> JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1993, Vol.48, No.8,
<> pp.5672-5674
<> IS: 0163-1829
<> DT: Note
<> AB: This paper describes some results obtained by using a
<> theoretical formulation of a long-wave phenomenological model
<> for polar optical phonons in heterostructures which takes full
<> account of (i) the coupling between the mechanical vibration u
<> and the electrostatic potential phi, (ii) the fact that u in
<> general has longitudinal and transverse parts, and (iii) the
<> simultaneous satisfaction of all mechanical and electrostatic
<> matching boundary conditions. The system of simultaneous
<> differential equations thus established is explicitly solved
<> without approximations. Two distinct classes of solutions are
<> obtained. One consists of shear horizontal purely mechanical
<> vibrations. The modes of the other class have mixed character
<> and describe coupled electrical and mechanical vibrations. The
<> results compare very well with experimental evidence and have
<> the correct symmetry pattern.
<> KP: ELECTRON-PHONON INTERACTION, GAAS/ALAS SUPERLATTICES, RAMAN-
<> SCATTERING, SYSTEMS, ALAS
<>
<> (88) TI: INTERACTION OF ELECTRONS WITH POLARITONS
<> AU: CONSTANTINOU_NC, ALDOSSARY_O, BABIKER_M
<> NA: UNIV ESSEX,DEPT PHYS,COLCHESTER CO4 3SQ,ESSEX,ENGLAND
<> JN: JOURNAL OF PHYSICS-CONDENSED MATTER, 1993, Vol.5, No.31,
<> pp.5581-5590
<> IS: 0953-8984
<> AB: The electromagnetic (EM) waves associated with the polariton
<> modes of bulk dielectrics are quantized using a procedure that
<> accounts for both the Em and matter fields. The interaction of
<> electrons with these polariton fields is described using the
<> minimal coupling (e/m*)A . p interaction Hamiltonian where A is
<> the transverse vector potential operator of the polariton
<> field, p the electronic momentum and m* its effective mass. The
<> electron-polariton interaction in the bulk is demonstrated to
<> be closely linked to the behaviour of the polariton group and
<> phase velocities. The same quantization procedure is then
<> employed to describe the EM fields associated with the
<> interface polaritons of a GaAs/AlAs quantum well system. The
<> coupling leads to a dependence of the scattering rate on the
<> group and phase velocities of the surface modes, just as it
<> does for the bulk excitations. In contrast to the case in the
<> bulk, it is shown that these modes are important for relaxing
<> the electron energy in narrow wells.
<> KP: PHONON INTERACTION, OPTICAL PHONONS, DOUBLE HETEROSTRUCTURES,
<> QUANTUM-WELLS, SUPERLATTICES, INTERFACE
<>
<> (89) TI: LONG-WAVELENGTH POLAR OPTICAL MODES IN GAAS SEMICONDUCTOR
<> LAYERED STRUCTURES
<> AU: PEREZALVAREZ_R, GARCIAMOLINER_F, VELASCO_VR, TRALLEROGINER_C
<> NA: CSIC,INST CIENCIA MAT,SERRANO 123,E-28006 MADRID,SPAIN
<> UNIV LA HABANA,DEPT FIS TEOR,HAVANA,CUBA
<> JN: JOURNAL OF PHYSICS-CONDENSED MATTER, 1993, Vol.5, No.31,
<> pp.5389-5400
<> IS: 0953-8984
<> AB: A long-wavelength model of polar optical modes coupling the
<> vibration amplitude u (the relative displacement vector) and
<> the electrostatic potential psi leads to a system of coupled
<> differential equations. This system is here solved for a
<> quantum well without approximations and with simultaneous
<> satisfaction of mechanical and electrostatic matching boundary
<> conditions. Explicit solutions for u and psi are given, and the
<> resulting eigenmodes for GaAs-based quantum wells are studied
<> in detail. The model gives modes with a mixed character
<> describing the coupling between u and psi. Thus one single
<> model yields confined quasi-longitudinal (strictly longitudinal
<> for in-plane wavelength vector kappa = 0), confined quasi-
<> transverse (strictly transverse for kappa = 0) and interface
<> modes. The dynamical structure, spectral strength and spatial
<> dependence of the relevant amplitudes are studied in detail.
<> The results are in good agreement with available Raman
<> experimental data and have all the basic features present in
<> microscopic calculations. Some comments are made on the
<> limitations of purely dielectric or purely mechanical models.
<> KP: ELECTRON-PHONON INTERACTION, RAMAN-SCATTERING, QUANTUM-WELLS,
<> SUPERLATTICES, SYSTEMS, ALAS, VIBRATIONS, INTERFACE, SURFACE
<>
<> (90) TI: IMPORTANCE OF CONFINED LONGITUDINAL OPTICAL PHONONS IN
<> INTERSUBBAND AND BACKWARD SCATTERING IN RECTANGULAR ALGAAS/GAAS
<> QUANTUM WIRES
<> AU: JIANG_W, LEBURTON_JP
<> NA: UNIV ILLINOIS,BECKMAN INST ADV SCI & TECHNOL,URBANA,IL,60801
<> JN: JOURNAL OF APPLIED PHYSICS, 1993, Vol.74, No.3, pp.2097-2099
<> IS: 0021-8979
<> DT: Note
<> AB: The important role of confined longitudinal optical (LO) and
<> surface optical (SO) phonons is investigated for different
<> types of individual scattering processes in AlGaAs/GaAs quantum
<> wires. Electron wave function tailing due to finite barrier
<> height has been properly taken into account. We demonstrate
<> that for highly confined wires structures L(y) = L(z) = 40
<> angstrom, forward and backward scattering are dominated by SO
<> phonons. For 80 angstrom x 80 angstrom structures, forward
<> scattering is still predominately by SO phonons while backward
<> scattering is dominated by confined LO phonons. Finally, for
<> 150 angstrom x 150 angstrom, confined phonons control both
<> forward and backward scattering. However, we demonstrate that
<> confined LO phonons play a dominant role in intersubband
<> transitions even in highly confined structures, and that it has
<> the most significant effect on the backward scattering in
<> quantum wires of L(y) = L(z) <> 80 angstrom.
<> KP: CARRIER CAPTURE, HETEROSTRUCTURES
<>
<> (91) TI: INFLUENCE OF IMPURITY AND PHONON-SCATTERING EFFECTS IN
<> RESONANT-TUNNELING STRUCTURES
<> AU: FU_Y, CHEN_Q, WILLANDER_M, BRUGGER_H, MEINERS_U
<> NA: LINKOPING UNIV,DEPT PHYS & MEASUREMENT TECHNOL,S-58183
<> LINKOPING,SWEDEN
<> DAIMLER BENZ AG,RES CTR,W-7900 ULM,GERMANY
<> JN: JOURNAL OF APPLIED PHYSICS, 1993, Vol.74, No.3, pp.1874-1878
<> IS: 0021-8979
<> AB: Tunneling properties and their temperature variations of
<> molecular bean epitaxy grown symmetric AlAs/GaAs/AlAs resonant
<> tunneling diodes with thin barriers are studied theoretically
<> and experimentally. The measured peak and valley current
<> densities show strong dependences on temperature. A Monte Carlo
<> simulation including impurity and optical-phonon scatterings is
<> developed for the calculation of the current-voltage behavior
<> of the double barrier structures. This approach reveals
<> pronounced temperature dependent tunneling features which agree
<> well with measured results.
<> KP: DOUBLE HETEROSTRUCTURES, INTRINSIC BISTABILITY, ELECTRON,
<> SUPERLATTICES, DIODES
<>
<> (92) TI: CONFINED AND INTERFACE-PHONON SCATTERING IN FINITE BARRIER
<> GAAS/ALGAAS QUANTUM WIRES
<> AU: JIANG_W, LEBURTON_JP
<> NA: UNIV ILLINOIS,BECKMAN INST ADV SCI & TECHNOL,URBANA,IL,61801
<> JN: JOURNAL OF APPLIED PHYSICS, 1993, Vol.74, No.3, pp.1652-1659
<> IS: 0021-8979
<> AB: We report on the calculation of the total scattering rate in
<> finite barrier GaAs/AlGa.As quantum wires based on the
<> interaction Hamiltonian of confined longitudinal optical (LO)
<> phonon and surface (SO) phonon modes. With multisubband
<> processes being properly taken into account, our calculation
<> indicates that for GaAs type of phonons the high-frequency
<> symmetric (s+) branch plays an important role among all the
<> other SO phonon branches; it can even dominate over confined LO
<> phonons in highly confined quantum wires as observed by K. W.
<> Kim, M. A. Stroscio, A. Bhatt, R. Mickevicius, and V. V. Mitin
<> [J. Appl. Phys. 70, 319 (1991)]. Our results also demonstrate
<> that the total contributions of confined LO and SO phonon
<> scattering resemble closely to GaAs bulk LO phonon scattering.
<> Selection rules between intersubband transitions for SO modes
<> suggest the possibility of a bottle-neck effect for carrier
<> relaxation in square wires compared with rectangular wires.
<> KP: ONE-DIMENSIONAL STRUCTURES, ELECTRON-GAS, DOUBLE
<> HETEROSTRUCTURES, MODES, SUPERLATTICES, CARRIERS, RATES, GAAS
<>
<> (93) TI: ELECTRON-INTERFACE LO PHONON-SCATTERING RATES IN QUANTUM-WELLS
<> IN A QUANTIZING MAGNETIC-FIELD
<> AU: BHAT_JS, MULIMANI_BG, KUBAKADDI_SS
<> NA: SDM COLL ENGN,DEPT PHYS,DHARWAR 580002,INDIA
<> KARNATAK UNIV,DEPT PHYS,DHARWAR 580003,KARNATAKA,INDIA
<> JN: JOURNAL OF APPLIED PHYSICS, 1993, Vol.74, No.7, pp.4561-4564
<> IS: 0021-8979
<> AB: Electron scattering rates due to interaction with interface
<> phonon modes in semiconductor quantum-well structures in a
<> quantizing magnetic field are studied. Numerical results for
<> scattering rates in GaAs/GaAlAs quantum wells show oscillatory
<> behavior with magnetic field. The scattering rate due to
<> interface phonon modes is found to decrease with the increase
<> of well width in contrast to that seen with bulk confined
<> phonons.
<> KP: DOUBLE HETEROSTRUCTURES, INTERSUBBAND RELAXATION, FROHLICH
<> INTERACTION, SUPERLATTICES, GAAS, ABSORPTION, MODES, ALAS
<>
<> (94) TI: SIMPLIFIED MICROSCOPIC MODEL FOR ELECTRON OPTICAL-PHONON
<> INTERACTIONS IN QUANTUM-WELLS
<> AU: BHATT_AR, KIM_KW, STROSCIO_MA, HIGMAN_JM
<> NA: N CAROLINA STATE UNIV,DEPT ELECT & COMP ENGN,RALEIGH,NC,27695
<> USA,RES OFF,RES TRIANGLE PK,NC,27709
<> UNIV ILLINOIS,BECKMAN INST,URBANA,IL,61801
<> JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1993, Vol.48, No.19,
<> pp.14671-14674
<> IS: 0163-1829
<> DT: Note
<> AB: A simplified microscopic model of optical phonons in
<> dimensionally confined structures is formulated and applied to
<> calculate electron-optical-phonon scattering rates in GaAs/AlAs
<> quantum wells. For this simplified model which circumvents
<> performing a complicated ab initio calculation of the force
<> constants at the interface, it is demonstrated that the
<> resulting dispersion relation and scattering rates for
<> electron-optical-phonon interactions agree very well with those
<> obtained from detailed ab initio studies. It is also shown that
<> for GaAs/A]As structures, the macroscopic dielectric continuum
<> model provides a good approximation to the scattering rate
<> predicted by the microscopic models.
<> KP: ZINCBLENDE STRUCTURE COMPOUNDS, LATTICE-DYNAMICS, GAAS/ALAS
<> SUPERLATTICES, FORCE-CONSTANTS, HETEROSTRUCTURES, GAAS,
<> POLARIZABILITY, SCATTERING, SYSTEMS
<>
<> (95) TI: EFFECTS OF A MAGNETOPOLARON IN CYLINDRICAL QUANTUM WIRES
<> AU: ZHOU_HY, GU_SW
<> NA: JIAO TONG UNIV,DEPT APPL PHYS,SHANGHAI 200030,PEOPLES R CHINA
<> JIAO TONG UNIV,INST CONDENSED MATTER PHYS,SHANGHAI
<> 200030,PEOPLES R CHINA
<> JN: SOLID STATE COMMUNICATIONS, 1993, Vol.88, No.4, pp.291-294
<> IS: 0038-1098
<> AB: Considering the interaction of the electron with surface-
<> optical (SO) phonons in polar crystals, we have studied the
<> cyclotron resonance of magnetopolaron in cylindrical quantum
<> wires. The results show that, with the increasing radius of the
<> quantum wire, both the electron-SO phonon interaction energy
<> and the cyclotron resonance frequency decrease mononically. For
<> the same radius of quantum wire, the cyclotron resonance
<> frequency increases almost linearly with the applied magnetic
<> field in the weak magnetic field limit.
<> KP: CYCLOTRON-RESONANCE, WELL WIRES, SINGLE
<>
<> (96) TI: COUPLING OF ELECTRONS TO INTERFACE PHONONS IN SEMICONDUCTOR
<> QUANTUM-WELLS - REPLY
<> AU: BABIKER_M, RIDLEY_BK
<> NA: UNIV ESSEX,DEPT PHYS,COLCHESTER CO4 3SQ,ESSEX,ENGLAND
<> JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1993, Vol.48, No.16,
<> pp.12342-12344
<> IS: 0163-1829
<> DT: Letter
<> AB: We consider the main points raised by Knipp and Reinecke (KR)
<> in their comments on our paper [Phys. Rev. B 43, 9096 (1991)].
<> We maintain that the interface modes described by KR are
<> interface polaritons and that they couple to electrons via a
<> minimal coupling in terms of a vector potential. We emphasize
<> that guided and bulk polaritons couple weakly to electrons via
<> an A.p interaction, in contrast to the interface polaritons,
<> which couple strongly to electrons, also via an A.p
<> interaction. We argue that in the radiation (or transverse)
<> gauge, the retarded interface modes have no scalar potential
<> (phi=0), and their vector potential has only a transverse
<> component A(perpendicular-to), and not both transverse and
<> longitudinal components. We point out that KR's retarded
<> electric fields are identical to ours, but maintain that our
<> use of only a transverse vector potential is appropriate. For
<> the wave vectors of interest to electron scattering, we agree
<> with KR that the fields are unretarded, but the interaction
<> remains in the minimal coupling form, simply involving the
<> unretarded limit of the same transverse vector potential. We
<> argue that only a unique unitary transformation applied to our
<> total unretarded minimally coupled Hamiltonian can lead to a
<> scalar potential form of the interaction, which we may denote
<> as ePHI, that is identical to that found by Mori and Ando
<> [Phys. Rev. B 40, 6175 (1989)]. The interaction Hamiltonian e
<> A(perpendicular-to).p/m* and the form ePHI associated with it
<> have different transition matrix elements, but they
<> nontrivially give identical results for all first-order
<> processes that are on the energy shell. We emphasize that the
<> outcome of all first-order transition-rate calculations
<> discussed by KR is indifferent to whether e A(perpendicular-
<> to).p/m* or ePHI is used.
<> KP: OPTICAL PHONONS, SUPERLATTICES, POLARITONS, MODES
<>
<> (97) TI: POLARON EFFECT ON THE BINDING-ENERGY OF A HYDROGENIC IMPURITY
<> IN A QUANTUM-WELL
<> AU: HAN_CS, PERNG_TM
<> NA: NATL CHIAO TUNG UNIV,DEPT ELECTROPHYS,HSINCHU,TAIWAN
<> JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1993, Vol.48, No.16,
<> pp.11965-11971
<> IS: 0163-1829
<> AB: We have studied the polaron effect on the binding energy of a
<> hydrogenic impurity in a quantum-well structure. The
<> interactions of an electron with both the confined bulk phonon
<> and the interface phonon are taken into account. The
<> competition between these two phonon modes is discussed. We
<> have also extended the calculation for the case of a finite
<> quantum well. It is found that the polaronic correction becomes
<> bigger as the potential barrier gets higher.
<> KP: ELECTRIC-FIELD DEPENDENCE, GAAS-ALAS SUPERLATTICES, LO-PHONON-
<> SCATTERING, INTERFACE PHONONS, RAMAN-SCATTERING, DOUBLE
<> HETEROSTRUCTURES, SHALLOW DONORS, CONFINED LO, HETEROJUNCTIONS,
<> STATES
<>
<> (98) TI: INTERFACE OPTICAL PHONONS NEAR PERFECTLY CONDUCTING BOUNDARIES
<> AND THEIR COUPLING TO ELECTRONS
<> AU: CONSTANTINOU_NC
<> NA: UNIV ESSEX,DEPT PHYS,COLCHESTER CO4 3SQ,ESSEX,ENGLAND
<> JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1993, Vol.48, No.16,
<> pp.11931-11935
<> IS: 0163-1829
<> AB: The interface optical phonon, are described for a GaAs/AlAs
<> system enclosed within metal (or superconductor) boundaries.
<> The requirement that the electrostatic potential associated
<> with these modes vanishes at these boundaries alters the
<> dispersion of the interface modes, especially that of the
<> antisymmetric vibrations. The interaction of electrons with
<> these modes is also considered, and a reduction in the rates is
<> obtained, in particular, when the AlAs width is less than the
<> GaAs width. As such, it is demonstrated that tampering with the
<> long-range Coulomb fields of the optical phonons by external
<> means, here by the proximity of perfectly conducting
<> interfaces, leads to a weakening of the Frohlich interaction by
<> effectively imposing a lower bound on the in-plane wave vector
<> which arises in the coupling function. This lower bound is
<> equal to the reciprocal of the AlAs width. In the special case
<> of a metal/GaAs/metal device, the carriers do not couple to
<> interface modes.
<> KP: GAAS-ALAS SUPERLATTICES, SEMICONDUCTOR HETEROSTRUCTURES,
<> QUANTUM-WELLS, LO PHONONS, EMISSION, MODES, WIRES
<>
<> (99) TI: BOTTLENECK EFFECTS DUE TO CONFINED PHONONS IN QUANTUM DOTS
<> AU: DELACRUZ_RM, TEITSWORTH_SW, STROSCIO_MA
<> NA: DUKE UNIV,DEPT PHYS,BOX 90305,DURHAM,NC,27708
<> USA,RES OFF,RES TRIANGLE PK,NC,27709
<> UCM,FAC CC FIS,DEPT FIS MAT,E-28040 MADRID,SPAIN
<> JN: SUPERLATTICES AND MICROSTRUCTURES, 1993, Vol.13, No.4, pp.481-
<> 486
<> IS: 0749-6036
<> KP: ELECTRON-GAS, SCATTERING, WIRE, MODES, SEMICONDUCTORS,
<> SUPERLATTICES, RELAXATION, SYSTEMS
<>
<> (100) TI: NORMALIZATION OF INTERFACE OPTICAL PHONON MODES IN CYLINDRICAL
<> QUANTUM WIRES WITH SEMICONDUCTOR-SEMICONDUCTOR AND METAL-
<> SEMICONDUCTOR BOUNDARY-CONDITIONS
<> AU: CHIU_CJ, STROSCIO_MA
<> NA: DUKE UNIV,DEPT ELECT ENGN,DURHAM,NC,27708
<> USA,RES OFF,RES TRIANGLE PK,NC,27709
<> JN: SUPERLATTICES AND MICROSTRUCTURES, 1993, Vol.13, No.4, pp.401-
<> 404
<> IS: 0749-6036
<> KP: ELECTRON, HETEROSTRUCTURES, SCATTERING, SYSTEMS, GROWTH
<>
<> (101) TI: ELECTRON - LO-PHONON SCATTERING RATES IN A CYLINDRICAL QUANTUM-
<> WIRE WITH AN AXIAL MAGNETIC-FIELD - ANALYTIC RESULTS
<> AU: MASALE_M, CONSTANTINOU_NC
<> NA: UNIV ESSEX,DEPT PHYS,COLCHESTER CO4 3SQ,ESSEX,ENGLAND
<> JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1993, Vol.48, No.15,
<> pp.11128-11134
<> IS: 0163-1829
<> AB: The interaction of electrons with bulk LO phonons in a
<> cylindrical quantum wire is discussed with both intersubband
<> and intrasubband relaxation considered. For processes involving
<> the lowest pair of subbands, a parallel analytic approach leads
<> to good agreement with the numerical calculations. In
<> particular, the effect of an axial magnetic field is determined
<> for intersubband transitions between these two subbands. It is
<> found that for a given radius, there is a critical magnetic
<> field beyond which first-order LO-phonon interactions are
<> forbidden due to energy conservation. Close to the critical
<> fields, fast intersubband relaxation is predicted. These
<> effects are a consequence of the Zeeman splitting of the doubly
<> degenerate states in the presence of the field and the behavior
<> of the one-dimensional density of states.
<> KP: ONE-DIMENSIONAL SEMICONDUCTOR, WELL WIRES, MOBILITY, RELAXATION,
<> SUBBANDS, GAS
<>
<> (102) TI: ELECTRON-OPTICAL PHONON INTERACTIONS IN POLAR SEMICONDUCTOR
<> QUANTUM-WELLS
<> AU: TSEN_KT
<> NA: ARIZONA STATE UNIV,DEPT PHYS & ASTRON,TEMPE,AZ,85287
<> JN: INTERNATIONAL JOURNAL OF MODERN PHYSICS B, 1993, Vol.7, No.25,
<> pp.4165-4185
<> IS: 0217-9792
<> AB: Electron-optical phonon interactions polar semiconductor
<> quantum wells are reviewed. Three macroscopic and one
<> microscopic models for electron-optical phonon interactions are
<> compared with experimental results in GaAs-AlAs polar
<> semiconductor quantum wells recently obtained by picosecond
<> time-resolved Raman spectroscopy. The macroscopic model of
<> Huang and Zhu as well as the microscopic model of Rucker et al.
<> are found to be in good agreement with the experimental data.
<> Direct measurements of electron-optical phonon scattering rates
<> in GaAs-AlAs polar semiconductor quantum wells carried out by
<> subpicosecond time-resolved Raman scattering technique are also
<> presented. These experimental results are explained with the
<> model of Huang and Zhu.
<> KP: RESOLVED RAMAN-SCATTERING, CONFINED LO, INTERSUBBAND RELAXATION,
<> DOUBLE HETEROSTRUCTURES, FROHLICH INTERACTION, GAAS,
<> SUPERLATTICES, MODES, SLAB
<>
<> (103) TI: POLAR OPTICAL OSCILLATIONS OF LAYERED SEMICONDUCTOR STRUCTURES
<> IN THE LONG-WAVELENGTH LIMIT
<> AU: COMAS_F, TRALLEROGINER_C
<> NA: HAVANA UNIV,DEPT THEORET PHYS,VEDADO 10400,CUBA
<> HAVANA UNIV,DEPT THEORET PHYS,VEDADO 10400,CUBA
<> JN: PHYSICA B, 1993, Vol.192, No.4, pp.394-402
<> IS: 0921-4526
<> AB: Polar optical oscillations coupled to unretarded electric
<> fields are discussed for the long-wavelength limit with
<> application to layered semiconductor structures (quantum wells,
<> superlattices, etc.). A Lagrangian formalism is adopted for the
<> deduction of the equations of both mechanical and electrical
<> quantities. The obtained equations bear the form of second-
<> order coupled differential equations for the fundamental
<> quantities, displacement field a and electric potential phi.
<> Matching boundary conditions are rigorously derived from the
<> equations and interpreted physically. The particular case of
<> materials belonging to the cubic symmetry is discussed with
<> special application to the double heterostructure. Some
<> comments are also made about the case of isotropic constituent
<> materials. We have thus settled a theory for long-wavelength
<> oscillations taking into account dispersion up to quadratic
<> terms in the wave vector (through the introduction of medium
<> internal stresses) with the aim of avoiding some problems which
<> have been detected and discussed in earlier treatments of this
<> subject.
<> KP: ELECTRON-PHONON INTERACTION, GAAS/ALAS SUPERLATTICES, RAMAN-
<> SCATTERING, QUANTUM-WELL, CONFINED LO, DOUBLE HETEROSTRUCTURES,
<> SYSTEMS, MODES
<>
<> (104) TI: INTRINSIC ELECTRON-MOBILITY IN NARROW GA0.47IN0.53AS QUANTUM-
<> WELLS
<> AU: MUKHOPADHYAY_S, NAG_BR
<> NA: CALCUTTA UNIV,92 ACHARYA PRAFULLA CHANDRA RD,CALCUTTA 700009,W
<> BENGAL,INDIA
<> JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1993, Vol.48, No.24,
<> pp.17960-17966
<> IS: 0163-1829
<> AB: Electron mobility in Ga0.47In0.53As quantum wells is calculated
<> for well widths between 2 and 10 nm and for the temperatures of
<> 4.2, 77, and 300 K. Effects of the finite barrier height,
<> energy-band nonparabolicity, mode confinement, electron
<> screening, and degeneracy have been taken into account. The
<> calculated values are found to be close to the experimental
<> results for a well-width of 10 nm. Effects of the composition
<> of the barrier layer are also discussed.
<> KP: SCATTERING-LIMITED-MOBILITY, PHONON INTERACTION,
<> HETEROSTRUCTURES, IN0.53GA0.47AS, TRANSPORT, SINGLE
<>
<> (105) TI: GROUND-STATE ENERGY AND EFFECTIVE-MASS OF AN INTERFACE POLARON
<> UNDER STRONG ELECTRON-PHONON INTERACTIONS
<> AU: YEUNG_YY, LAI_ZY, GU_SW, LI_WS, AUYEUNG_TC
<> NA: HONG KONG POLYTECH,DEPT APPL PHYS,HONG KONG,HONG KONG
<> SHANGHAI JIAO TONG UNIV,DEPT APPL PHYS,SHANGHAI 20030,PEOPLES R
<> CHINA
<> CCAST,WORLD LAB,BEIJING 100080,PEOPLES R CHINA
<> SHANGHAI JIAO TONG UNIV,INST CONDENSED MATTER PHYS,SHANGHAI
<> 200030,PEOPLES R CHINA
<> HONG KONG POLYTECH,DEPT ELECTR ENGN,HONG KONG,HONG KONG
<> NANYANG TECHNOL UNIV,SCH ELECT & ELECTR ENGN,SINGAPORE
<> 2263,SINGAPORE
<> JN: PHYSICS LETTERS A, 1993, Vol.183, No.5-6, pp.418-424
<> IS: 0375-9601
<> AB: For an electron interacting strongly with both the interface
<> optical phonons and the bulk longitudinal optical (LO) phonons,
<> the properties of a polaron bound at the interface between two
<> semi-infinite polar crystals are studied. The important effect
<> of the normally ignored electron-bulk LO phonon interaction is
<> demonstrated.
<> KP: STRONG-COUPLED POLARONS, SELF-TRAPPING ENERGY, SURFACE POLARONS,
<> MAGNETIC-FIELD, CYCLOTRON MASS, ALKALI-HALIDES
<>
<> (106) TI: ACOUSTIC-PHONON SCATTERING IN A RECTANGULAR QUANTUM-WIRE
<> AU: MICKEVICIUS_R, MITIN_V
<> NA: WAYNE STATE UNIV,DEPT ELECT & COMP ENGN,DETROIT,MI,48202
<> JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1993, Vol.48, No.23,
<> pp.17194-17201
<> IS: 0163-1829
<> AB: The rates of electron scattering by acoustic phonons in a
<> rectangular quantum wire embedded into another material are
<> calculated in the framework of the Fermi golden rule. Both
<> intrasubband and intersubband electron scattering by acoustic
<> phonons are considered. It has been shown that due to
<> uncertainty of momentum conservation in quasi-one-dimensional
<> systems the acoustic-phonon scattering becomes essentially
<> inelastic in contrast to that in bulk materials. The acoustic-
<> phonon scattering rate in quantum wires increases with the
<> decrease of cross section of the wire and is much greater than
<> that in bulk materials. It is shown that the correct treatment
<> of inelasticity leads to a nonmonotonic dependence of the
<> emission rate on electron energy and to the disappearance of
<> the divergency of the acoustic-phonon scattering rate at the
<> bottom of each subband. Therefore, the scattering time averaged
<> over the distribution function exceeds considerably that
<> calculated using elastic and quasielastic approaches where the
<> scattering rate is divergent. We demonstrate that electron
<> mobility at temperatures less than 100 K calculated within
<> elastic or quasielastic approximations is greatly
<> underestimated.
<> KP: ELECTRON-TRANSPORT, HOT-ELECTRONS, MOBILITY, SYSTEMS, ENERGY
<>
<> (107) TI: NUMERICAL-SIMULATION OF ELECTRON-TRANSPORT IN MESOSCOPIC
<> STRUCTURES WITH WEAK DISSIPATION
<> AU: REGISTER_LF, HESS_K
<> NA: UNIV ILLINOIS,BECKMAN INST,URBANA,IL,61801
<> JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1994, Vol.49, No.3,
<> pp.1900-1907
<> IS: 0163-1829
<> AB: A numerical method for simulating transient through steady-
<> state electron transport in multidimensional mesoscopic
<> structures in the presence of weak electron-phonon interactions
<> is presented. This method allows both visualization and
<> quantitative analysis of such electron-phonon coupling
<> processes in these structures. To allow simulation of quantum
<> interference effects within multidimensional structures, a
<> previously developed method for simulating dissipationless
<> transport based on the time-dependent Schrodinger equation is
<> used as a starting point. Then, to allow simulation of the
<> effects of electron-phonon coupling yet retain numerical
<> tractability, a limited number of discretized harmonic
<> oscillator degrees of freedom are added to those of the
<> electron. Coupling between the electron and oscillator degrees
<> of freedom is via Monte Carlo sampled potential functions that
<> are obtained rom the true electron-phonon coupling potentials.
<> The method is exact to first order in the coupling and models
<> some higher order coupling processes as well. Example
<> simulations are performed for both real emission of polar-
<> optical phonons and self-energy processes in prototypical
<> mesoscopic structures.
<> KP: OPTICAL-PHONON-SCATTERING, HETEROSTRUCTURES, SEMICONDUCTORS,
<> CARRIERS
<>
<> (108) TI: LO-PHONON EMISSION BY HOT-ELECTRONS IN ONE-DIMENSIONAL
<> SEMICONDUCTOR QUANTUM WIRES
<> AU: DASSARMA_S, CAMPOS_VB
<> NA: UNIV MARYLAND,DEPT PHYS,COLL PK,MD,20742
<> UNIV FED SAO CARLOS,DEPT FIS,SAO PAULO,SP,BRAZIL
<> JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1994, Vol.49, No.3,
<> pp.1867-1874
<> IS: 0163-1829
<> AB: We provide a theoretical study of hot-electron energy loss via
<> LO-phonon emission in GaAs quantum wires. Calculations are done
<> for a model in which the hot-electron gas is described by a
<> temperature T which is much higher than the lattice
<> temperature. We take into account several relevant physical
<> mechanisms such as quantum degeneracy, dynamic screening,
<> quantum confinement, and hot-phonon bottleneck effect. We
<> include the effects of quantum-wire phonon confinement using
<> two prevailing boundary conditions, namely, the so-called
<> electrostatic and the mechanical macroscopic models. The
<> energy-loss rate calculated for the bulk LO-phonon emission is
<> comparable to, but somewhat higher than, that due to slab
<> (electrostatic) phonon emission, whereas the guided
<> (mechanical) modes produce more than an order of magnitude
<> slower energy relaxation than that due to the slab
<> (electrostatic) or the bulk modes. Our results show that in the
<> experimentally interesting electron-temperature range of 50-300
<> K, the hot-phonon bottleneck is the single most important
<> quantitative effect provided the hot-phonon lifetime in GaAs
<> quantum wires is comparable to that (similar to 5-7 ps) in the
<> bulk GaAs. The numerical magnitudes of the quantum-wire hot-
<> electron energy-loss rate due to LO-phonon emission are
<> comparable to those in quantum-well structures under comparable
<> conditions.
<> KP: DOUBLE HETEROSTRUCTURES, CARRIER RELAXATION, ENERGY RELAXATION,
<> WELL-WIRES, GAAS, EXCITATIONS, MICROSTRUCTURES, SPECTROSCOPY,
<> SCATTERING, SYSTEMS
<>
<> (109) TI: EFFECT OF SCATTERING ON THE RESONANT-TUNNELING CURRENT IN
<> DOUBLE-BARRIER STRUCTURES
<> AU: ZOU_NZ, CHEN_Q, WILLANDER_M
<> NA: LINKOPING UNIV,DEPT PHYS & MEASUREMENT TECHNOL,S-58183
<> LINKOPING,SWEDEN
<> JN: JOURNAL OF APPLIED PHYSICS, 1994, Vol.75, No.3, pp.1829-1831
<> IS: 0021-8979
<> DT: Note
<> AB: The scattering effect on resonant tunneling current for double-
<> barrier resonant tunneling diode is investigated. It is clearly
<> shown that while the elastic scattering effect is negligible,
<> the inelastic scattering will suppress the resonant tunneling
<> current by breaking:the phase coherence. An expression for the
<> current suppression is obtained. The inelastic scattering
<> effect is also dominant for the temperature dependence of peak
<> current. The numerical result is in good agreement with the
<> experiment result.
<> KP: INTERFACE-ROUGHNESS, PHONON INTERACTION, SOLVABLE MODEL,
<> HETEROSTRUCTURES
<>
<> (110) TI: TRANSITIONS BETWEEN GAMMA AND X STATES OF SHORT-PERIOD
<> SUPERLATTICES DRIVEN BY ANTISYMMETRIC INTERFACE PHONONS
<> AU: STROSCIO_MA, DUTTA_M, ZHANG_XQ
<> NA: USA,RES OFF,POB 12211,RES TRIANGLE PK,NC,27709
<> USA,RES LAB,ELECTR & POWER SOURCES DIRECTORATE,FT
<> MONMOUTH,NJ,07703
<> DUKE UNIV,DEPT ELECT ENGN,DURHAM,NC,27708
<> JN: JOURNAL OF APPLIED PHYSICS, 1994, Vol.75, No.4, pp.1977-1981
<> IS: 0021-8979
<> AB: Relative transition probability amplitudes for antisymmetric-
<> interface-phonon-assisted GAMMA-X transitions in selected
<> short-period superlattices are estimated by using the
<> dielectric continuum model for antisymmetric interface optical
<> phonons in conjunction with a Kronig-Penney model of the
<> superlattice electronic properties.
<> KP: GAAS/ALAS QUANTUM-WELLS, SEMICONDUCTOR HETEROINTERFACES,
<> MINIBAND STRUCTURE, ENVELOPE FUNCTIONS, HETEROSTRUCTURES,
<> CONNECTION, EXCITON
<>
<> (111) TI: POLAR-OPTIC PHONONS AND HIGH-FIELD ELECTRON-TRANSPORT IN
<> CYLINDRICAL GAAS/ALAS QUANTUM WIRES
<> AU: WANG_XF, LEI_XL
<> NA: CHINESE ACAD SCI,SHANGHAI INST MET,865 CHANGNING RD,SHANGHAI
<> 200050,PEOPLES R CHINA
<> CHINA CTR ADV SCI & TECHNOL,WORLD LAB,BEIJING 100080,PEOPLES R
<> CHINA
<> JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1994, Vol.49, No.7,
<> pp.4780-4789
<> IS: 0163-1829
<> AB: Linear and nonlinear electron transport in GaAs/AlAs
<> cylindrical quantum wires is investigated with the help of the
<> balance-equation transport theory. Confined phonons, surface
<> phonons, and their Frohlich couplings with electrons in these
<> quasi-one-dimensional electron-phonon systems are described
<> using the dielectric continuum, hydrodynamic continuum, and
<> Huang-Zhu optic-phonon models, respectively. Both intrasubband
<> and intersubband transitions of up to 21 electron subbands are
<> taken into account in the numerical calculation. The comparison
<> of the results from these three models with those obtained by
<> using bulk phonon approximation shows that the bulk phonon
<> approximation is accurate enough to describe the Frohlich
<> interaction when calculating the linear and nonlinear electron
<> transport even in ultrafine GaAs/AlAs quantum wires.
<> KP: LO PHONONS, SCATTERING RATES, CONFINED LO, SEMICONDUCTOR
<> SUPERLATTICES, CONTINUUM-THEORIES, INTERFACE PHONONS, RAMAN-
<> SCATTERING, BRIEF CRITIQUE, WELLS, MODES
<>
<> (112) TI: A POLARON IN A QUANTUM-WELL WITHIN AN ELECTRIC-FIELD
<> AU: CHEN_CY, LIANG_SD, LI_M
<> NA: CCAST,WORLD LAB,CTR THEORET PHYS,POB 8730,BEIJING
<> 100080,PEOPLES R CHINA
<> GUANGZHOU TEACHERS COLL,DEPT PHYS,CANTON 510400,PEOPLES R CHINA
<> S CHINA NORMAL UNIV,DEPT PHYS,CANTON 510631,PEOPLES R CHINA
<> JN: JOURNAL OF PHYSICS-CONDENSED MATTER, 1994, Vol.6, No.10,
<> pp.1903-1912
<> IS: 0953-8984
<> AB: The ground-state energy and effective mass of a polaron in the
<> quantum well (QW) of an AlAs/GaAs double heterostructure (DHS)
<> are calculated as functions of the well width and the strength
<> of the electric field applied along the growth direction. Every
<> type of optical phonon mode that can exist in the DHS within
<> the continuous model is considered separately. It is found that
<> the contribution of the interface phonon to the polaron effect
<> is much larger than that of the confined bulk phonon modes in
<> QWS with width d < 50 angstrom and then falls quickly with
<> increasing well width up to d congruent-to 200 angstrom. An
<> electric field has hardly any influence on polaron effects in
<> Qws with width d < 50 angstrom, but when d <> 50 angstrom the
<> influence becomes much stronger. The correction of the ground-
<> state energy and effective mass originating from LO modes
<> decreases and that from the interface modes increases with
<> increasing strength of the electric field.
<> KP: HETEROSTRUCTURES, SCATTERING, SINGLE, ENERGY, SUPERLATTICES,
<> LUMINESCENCE, PHONONS, MODES, MASS, GAS
<>
<> (113) TI: PROPERTIES OF AN INTERFACE POLARON IN A MAGNETIC-FIELD OF
<> ARBITRARY STRENGTH
<> AU: WEI_BH, YU_KW, OU_F
<> NA: S CHINA UNIV TECHNOL,DEPT APPL PHYS,CANTON 510641,PEOPLES R
<> CHINA
<> CHINESE CTR ADV SCI & TECHNOL,BEIJING 100080,PEOPLES R CHINA
<> INT CTR MAT PHYS,SHENYANG 110015,PEOPLES R CHINA
<> CHINESE UNIV HONG KONG,DEPT PHYS,SHA TIN,HONG KONG
<> JN: JOURNAL OF PHYSICS-CONDENSED MATTER, 1994, Vol.6, No.10,
<> pp.1893-1902
<> IS: 0953-8984
<> AB: We study the induced potential of an interface electron
<> interacting with bulk longitudinal-optical (BO) phonons as well
<> as interface optical (IO) phonons using the Green-function
<> method. The dependence of the induced potential on the magnetic
<> field strength and on the distance of the electron from the
<> interface is studied. The numerical results show that in weak
<> magnetic fields both \V(e-BO)\ and \V(e-IO)\ are rapidly
<> increasing functions of the magnetic field, but beyond a
<> critical magnetic field B(c), \V(e-BO)\ and \V(e-IO)\ are
<> slowly decreasing functions of the magnetic field. The
<> numerical results also show that the electron-IO phonon
<> interaction is dominant for weak magnetic fields and small
<> electron departure from the interface. In the opposite limit,
<> the electron-BO phonon interaction is dominant.
<> KP: ELECTRON-PHONON INTERACTION, SELF-TRAPPING ENERGY, TEMPERATURE-
<> DEPENDENCE, CYCLOTRON-RESONANCE, MAGNETOPOLARON, DIMENSIONS,
<> MASS
<>
<> (114) TI: OSCILLATORY MAGNETOCONDUCTIVITY OF A 2-DIMENSIONAL ELECTRON-
<> SYSTEM DUE TO PHONON-SCATTERING
<> AU: CHAUBEY_MP
<> NA: DAWSON COLL GEN & PROFESS EDUC,DEPT MATH & PHYS,3040 SHERBROOKE
<> ST W,MONTREAL H3Z 1A4,PQ,CANADA
<> MCGILL UNIV,DEPT CHEM,MONTREAL H3A 2K6,QUEBEC,CANADA
<> JN: NUOVO CIMENTO DELLA SOCIETA ITALIANA DI FISICA D-CONDENSED
<> MATTER ATOMIC MOLECULAR AND CHEMICAL PHYSICS FLUIDS PLASMAS
<> BIOPHYSICS, 1993, Vol.15, No.12, pp.1539-1548
<> IS: 0392-6737
<> AB: A quantum-statistical theory of magnetophonon resonance
<> oscillations in two-dimensional systems has been developed,
<> starting from the resolvent representation of Kubo's formula
<> and its proper connected diagram expansion. Non-polar and polar
<> optical-phonon scattering has been considered and the results
<> show, as anticipated based on the physical considerations and
<> experimental observations, conductivity oscillations as a
<> function of magnetic field with the magnetophonon resonances
<> occurring at the phonon frequencies omega0 = Pomega(c) (P = 1,
<> 2, 3, ..., omega(c) = cyclotron frequency). Divergences
<> occurring in the magnetoconductivity near the magnetophonon
<> resonances are removed by using the full resolvent operator in
<> the tetradic self-energy operator of an electron. These
<> additional terms provide necessary damping of the magnetophonon
<> resonance oscillations. The present results are also shown to
<> be qualitatively similar to those obtained by others using
<> quantum Boltzmann's equation approach to quantum transport
<> theory.
<> KP: DIMENSIONAL MAGNETOPHONON RESONANCE, QUASI-2-DIMENSIONAL
<> QUANTUM WELLS, INP SUPER-LATTICES, CYCLOTRON-RESONANCE,
<> MAGNETIC-FIELD, GAS, HETEROSTRUCTURES, GAAS, PHOTOLUMINESCENCE,
<> HETEROJUNCTIONS
<> WA: THEORY OF ELECTRONIC TRANSPORT, SCATTERING MECHANISMS,
<> ELECTRONIC TRANSPORT IN INTERFACE STRUCTURES, MEASUREMENT OF
<> FERMI SURFACE PARAMETERS (INCLUDING DHVA, MAGNETOACOUSTIC,
<> MAGNETORESISTANCE OSCILLATION, AND CYCLOTRON RESONANCE STUDIES,
<> ETC), POLARONS AND ELECTRON-PHONON INTERACTIONS
<>
<> (115) TI: EFFECT OF HALF-SPACE AND INTERFACE PHONONS ON THE TRANSPORT-
<> PROPERTIES OF ALXGA1-XAS/GAAS SINGLE HETEROSTRUCTURES
<> AU: BORDONE_P, LUGLI_P
<> NA: ARIZONA STATE UNIV,CTR SOLID STATE ELECTR RES,TEMPE,AZ,85287
<> UNIV MODENA,IST NAZL FIS,I-41100 MODENA,ITALY
<> UNIV MODENA,DIPARTIMENTO FIS,I-41100 MODENA,ITALY
<> JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1994, Vol.49, No.12,
<> pp.8178-8190
<> IS: 0163-1829
<> AB: We present a detailed analysis of the influence of the various
<> phonon modes characteristic of the single heterostructure
<> AlxGa1-xAs/GaAs on its electronic transport by using a Monte
<> Carlo simulation. The electronic states of the system are
<> calculated by solving self-consistently the coupled
<> Schrodinger-Poisson equations for the system. LO-phonon states
<> are treated within the dielectric continuum model by using two
<> different dielectric functions to describe the two
<> semiconductors, the usual Lyddane-Sachs-Teller expression for
<> GaAs and a generalized two poles expression for AlxGa1-xAs. Two
<> sets of optical modes characterize the system, the half-space
<> LO modes and the interface modes. The scattering rates for the
<> interaction of these modes with the confined electrons are
<> calculated from the Fermi golden rule. A Monte Carlo simulation
<> is then used to study the effect of the electron-phonon
<> interaction on the transport properties of a single AlxGa1-
<> xAs/GaAs heterostructure in the presence of an electric field
<> applied along the heterointerface. The results of simulations
<> performed at 300 and 77 K compare favorably with available
<> experimental data. Drag and heating effects related to
<> nonequilibrium phonon effects are found and discussed.
<> KP: QUANTUM-WELLS, MONTE-CARLO, DOPED HETEROSTRUCTURES, POLAR
<> SEMICONDUCTORS, ELECTRON VELOCITY, HETEROJUNCTIONS, SCATTERING,
<> DYNAMICS, SUBBANDS, GAAS
<>
<> (116) TI: EFFECT OF THE ELECTRON SURFACE-OPTICAL-PHONON INTERACTION ON
<> THE IMPURITY-STATE ENERGIES IN A SEMICONDUCTOR QUANTUM-WELL
<> AU: SHEN_ZJ, YUAN_XZ, SHEN_GT, YANG_BC
<> NA: CHINA CTR ADV SCI & TECHNOL,WORLD LAB,POB 8730,BEIJING
<> 100080,PEOPLES R CHINA
<> E CHINA NORMAL UNIV,DEPT PHYS,SHANGHAI 200062,PEOPLES R CHINA
<> JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1994, Vol.49, No.16,
<> pp.11035-11039
<> IS: 0163-1829
<> AB: Using a variational technique, the change of ground-state
<> energy and binding energy of an impurity atom with impurity
<> position and well width in a GaAs-Ga0.7Al0.3As quantum well is
<> calculated. In the calculation the electron-surface-optical-
<> phonon interactions are taken into account. The result is
<> discussed. It is found that the electron-phonon interaction
<> energy depends not only on the width of the well but also on
<> the position of the impurity atom in the well.
<> KP: SPECTRA, SLAB, POLARON, DONORS, MODEL
<>
<> (117) TI: BIPOLARON CONFINEMENT IN 2-DIMENSIONAL LAYERS
<> AU: FOMIN_VM, SMONDYREV_MA
<> NA: MARTIN LUTHER UNIV HALLE WITTENBERG,D-06108 HALLE,GERMANY
<> JOINT INST NUCL RES,BOGOLIUBOV THEORET LAB,141980 DUBNA,RUSSIA
<> STATE UNIV MOLDAVIA,DEPT THEORET PHYS,277014 KISHINEV,MOLDOVA
<> JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1994, Vol.49, No.18,
<> pp.12748-12753
<> IS: 0163-1829
<> AB: Widely reported broadening of a bipolaron formation region in
<> two dimensions should be revised in view of a concrete
<> mechanism of electron confinement to a two-dimensional layer.
<> KP: ELECTRON-PHONON INTERACTION, SEMICONDUCTOR QUANTUM-WELLS, HIGH-
<> TEMPERATURE SUPERCONDUCTIVITY, WAVELENGTH OPTICAL PHONONS,
<> GAAS-ALAS SUPERLATTICES, MULTILAYER STRUCTURES, DOUBLE
<> HETEROSTRUCTURES, CONTINUUM-THEORIES, BRIEF CRITIQUE, 3
<> DIMENSIONS
<>
<> (118) TI: HOT-ELECTRON OVERCOOLING AND INTERSUBBAND POPULATION-INVERSION
<> IN QUANTUM WIRES
<> AU: GASKA_R, MICKEVICIUS_R, MITIN_V, GRUBIN_HL
<> NA: WAYNE STATE UNIV,DEPT ELECT ENGN,DETROIT,MI,48202
<> SCI RES ASSOCIATES INC,GLASTONBURY,CT,06033
<> JN: SEMICONDUCTOR SCIENCE AND TECHNOLOGY, 1994, Vol.9, No.5 SS,
<> pp.886-888
<> IS: 0268-1242
<> AB: Monte Carlo simulation of hot photoexcited electron relaxation
<> in rectangular quantum wires is carried out. Simulation shows
<> that at the initial stage the electron cooling dynamics is
<> defined by electron-optical phonon interaction and exhibits
<> strong dependence on excitation energy. When electrons are
<> excited above the optical phonon energy they cool down in a
<> subpicosecond time-scale to the bottom of the first subband.
<> Electrons may even occur below thermal equilibrium energy and
<> then slowly (during tens of picoseconds) relax to equilibrium
<> due to interaction with acoustic phonons. At certain excitation
<> energies strong intersubband electron scattering by optical
<> phonons leads to carrier redistribution and intersubband
<> population inversion.
<> KP: PHONON INTERACTION
<>
<> (119) TI: PHONON EFFECTS ON ELECTRONIC TRANSPORT IN SINGLE ALXGA1-XAS
<> GAAS HETEROJUNCTIONS
<> AU: BORDONE_P, LUGLI_P, GULIA_M
<> NA: UNIV MODENA,DIPARTIMENTO FIS,I-41100 MODENA,ITALY
<> UNIV MODENA,IST NAZL FIS MAT,I-41100 MODENA,ITALY
<> UNIV ROMA TOR VERGATA,DIPARTIMENTO INGN ELETTR,I-00133
<> ROME,ITALY
<> JN: SEMICONDUCTOR SCIENCE AND TECHNOLOGY, 1994, Vol.9, No.5 SS,
<> pp.820-823
<> IS: 0268-1242
<> AB: We have studied the transport properties of an AlxGa1-xAs/GaAs
<> single heterostructure using a Monte Carlo method, focusing in
<> particular on the effect of the polar interaction between
<> electrons and phonons. A two-valley (GAMMA and L) model for
<> both GaAs and AlxGa1-xAs layers has been used, which includes
<> size quantization effects through the numerical self-consistent
<> solution of the coupled Schrodinger-Poisson equations. The
<> optical mode description is given in terms of the dielectric
<> continuum model (DCM); within this model the alloy is described
<> by a two-pole dielectric function, which depends on the Al
<> composition. We have then evaluated the scattering
<> probabilities for the confined electrons interacting with half-
<> space and interface modes. These rates are inserted in our
<> Monte Carlo code to study the electron response to an electric
<> field applied along the heterointerface.
<> KP: QUANTUM WELLS, MONTE-CARLO, DOUBLE HETEROSTRUCTURES, DOPED
<> HETEROSTRUCTURES, POLAR SEMICONDUCTORS, VELOCITY
<>
<> (120) TI: HOT-ELECTRON RELAXATION VIA THE EMISSION OF GAAS OPTICAL MODES
<> AND ALAS INTERFACE MODES IN GAAS ALAS MULTIQUANTUM WELLS
<> AU: OZTURK_E, CONSTANTINOU_NC, STRAW_A, BALKAN_N, RIDLEY_BK,
<> RITCHIE_DA, LINFIELD_EH, CHURCHILL_AC, JONES_GAC
<> NA: UNIV ESSEX,DEPT PHYS,COLCHESTER CO4 3SQ,ESSEX,ENGLAND
<> UNIV CAMBRIDGE,CAVENDISH LAB,CAMBRIDGE CB3 0HE,ENGLAND
<> JN: SEMICONDUCTOR SCIENCE AND TECHNOLOGY, 1994, Vol.9, No.5 SS,
<> pp.782-785
<> IS: 0268-1242
<> AB: We demonstrate via hot-electron photoluminescence and high-
<> temperature mobility measurements the importance of the AlAs
<> interface mode in the energy relaxation of electrons in
<> GaAs/AlAs multi-quantum wells. A corresponding investigation of
<> a similar GaAs/Al0.24Ga0.76As system illustrates that this is
<> not the case for AlGaAs barrier devices where GaAs modes are
<> the dominant energy relaxation process. The importance of the
<> AlAs interface mode is not simply related to its intrinsic
<> scattering rate but also to its shorter lifetime (compared with
<> GaAs modes). Hot-phonon effects are therefore crucial to a full
<> understanding of the experimental data.
<> KP: DOUBLE HETEROSTRUCTURES, PHONON INTERACTIONS, TRANSPORT
<>
<> (121) TI: PHONON CONFINEMENT EFFECT OBSERVED IN LONGITUDINAL
<> MAGNETOPHONON RESONANCE IN AL0.3GA0.7AS GAAS SUPERLATTICES WITH
<> WITHOUT ALAS THIN BARRIERS
<> AU: NOGUCHI_H, SAKAKI_H, TAKAMASU_T, MIURA_N
<> NA: UNIV TOKYO,ADV SCI & TECHNOL RES CTR,4-6-1 KOMABA,MEGURO
<> KU,TOKYO 153,JAPAN
<> UNIV TOKYO,INST IND SCI,MINATO KU,TOKYO 106,JAPAN
<> UNIV TOKYO,INST SOLID STATE PHYS,MINATO KU,TOKYO 106,JAPAN
<> JN: SEMICONDUCTOR SCIENCE AND TECHNOLOGY, 1994, Vol.9, No.5 SS,
<> pp.778-781
<> IS: 0268-1242
<> AB: Electron-optical phonon interaction is studied in longitudinal
<> transport through a series of Al0.3Ga0.7As/GaAs superlattices
<> by measuring longitudinal magnetophonon resonance (MPR). In
<> addition to well resolved MPR peaks caused by GaAs phonons,
<> peaks ascribable to AlAs interface phonons are observed when a
<> thin AlAs barrier is inserted at each GaAs/Al0.3Ga0.7As
<> heterointerface. A calculation based on the Huang-Zhu model
<> describes the features of experimental spectra. When the well
<> width is reduced in Al0.3Ga0.7As/GaAs superlattices with narrow
<> quantum wells, the AlAs-like phonon mode also becomes important
<> in miniband transport.
<> KP: MULTIPLE QUANTUM-WELLS, LO PHONONS, ELECTRON, SCATTERING,
<> RELAXATION, TRANSPORT, SINGLE
<>
<> (122) TI: POLARONS IN QUASI-2-DIMENSIONAL STRUCTURES
<> AU: THILAGAM_A, SINGH_J
<> NA: NO TERR UNIV,FAC SCI,POB 40146,CASUARINA,NT 0811,AUSTRALIA
<> JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1994, Vol.49, No.19,
<> pp.13583-13588
<> IS: 0163-1829
<> AB: A theory of quasi-two-dimensional (2D) polarons in
<> semiconductor quantum wells is presented. We have derived
<> analytical expressions for the energy-gap shift and effective
<> polaron mass in the small-well-width limit. The analytical
<> results agree exactly with those obtained for an ideal 2D
<> system in the limit of zero well width. For larger quantum-well
<> widths, we have numerically evaluated the values for the
<> energy-gap shift and effective mass of a polaron.
<> KP: ELECTRON-PHONON INTERACTION, QUANTUM-WELLS, SLAB, GAS
<>
<> (123) TI: POLAR OPTICAL OSCILLATION MODES IN GAAS-BASED DOUBLE
<> HETEROSTRUCTURES - LONG-WAVELENGTH LIMIT
<> AU: COMAS_F, PEREZALVAREZ_R, TRALLEROGINER_C, CARDONA_M
<> NA: HAVANA UNIV,DEPT THEORET PHYS,VEDADO,10400 HAVANA,CUBA
<> MAX PLANCK INST FESTKORPERFORSCH,D-70569 STUTTGART,GERMANY
<> JN: SUPERLATTICES AND MICROSTRUCTURES, 1993, Vol.14, No.1, pp.95-
<> 104
<> IS: 0749-6036
<> KP: ELECTRON-PHONON INTERACTION, GAAS/ALAS SUPERLATTICES,
<> SEMICONDUCTOR SUPERLATTICES, RAMAN-SCATTERING, DISPERSION,
<> SYSTEMS, INTERFACE, SPECTRA
<>
<> (124) TI: LOCALIZED PHONON-ASSISTED CYCLOTRON-RESONANCE IN GAAS/ALAS
<> QUANTUM-WELLS
<> AU: BHAT_JS, MULIMANI_BG, KUBAKADDI_SS
<> NA: KARNATAK UNIV,DEPT PHYS,DHARWAR 580003,KARNATAKA,INDIA
<> KARNATAK UNIV,DEPT PHYS,DHARWAR 580003,KARNATAKA,INDIA
<> SRI DHARMASTHALA MANJUNATHESHWARA COLL ENGN,DEPT PHYS,DHARWAR
<> 580002,INDIA
<> JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1994, Vol.49, No.23,
<> pp.16459-16466
<> IS: 0163-1829
<> AB: The theory of phonon-assisted cyclotron resonance in quantum
<> wells is given; we consider cases where electrons are scattered
<> by confined LO phonons described by the Huang and Zhu model,
<> Fuchs-Kliewer slab modes, and Ridley's guided mode model. The
<> effect of interface phonon modes on cyclotron resonance is also
<> studied. Extra peaks due to transitions between Landau levels
<> accompanied by emission of confined and interface phonons in
<> the absorption spectrum are predicted. Numerical results for
<> frequency, field, and well-width dependence are given for
<> parameters characteristic of GaAs/AlAs quantum wells.
<> KP: FREE-CARRIER ABSORPTION, QUASI-2-DIMENSIONAL SEMICONDUCTING
<> STRUCTURES, QUANTIZING MAGNETIC-FIELD, SCATTERING RATES, DOUBLE
<> HETEROSTRUCTURES, ELECTRIC-FIELD, INTERSUBBAND TRANSITIONS,
<> FROHLICH INTERACTION, INTERFACE PHONONS, CONDUCTION-BAND
<>
<> (125) TI: ELECTRON - INTERFACE-PHONON SCATTERING IN GRADED QUANTUM-WELLS
<> OF GA1-XALXAS
<> AU: DUAN_WH, ZHU_JL, GU_BL
<> NA: CENT IRON & STEEL RES INST,BEIJING 100081,PEOPLES R CHINA
<> WORLD LAB,CHINESE CTR ADV SCI & TECHNOL,CTR THEORET
<> PHYS,BEIJING 100080,PEOPLES R CHINA
<> TSING HUA UNIV,DEPT PHYS,BEIJING 100084,PEOPLES R CHINA
<> JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1994, Vol.49, No.20,
<> pp.14403-14408
<> IS: 0163-1829
<> AB: Using the method of series expansion, interface-phonon
<> vibrational modes are calculated in the dielectric continuum
<> model for the graded quantum well of Ga1-xAlxAs with a
<> Ga0.6Al0.4As barrier. The intrasubband and intersubband
<> scattering rates are obtained as functions of quantum-well
<> width. The results reveal that the behavior of interface phonon
<> modes is very different from that in a square quantum-well
<> structure. It is found that the electron-interface-phonon
<> scattering rates can be changed remarkably in a graded quantum-
<> well structure compared with those in a square quantum-well
<> structure, which is useful for some device applications.
<> KP: SEMICONDUCTOR HETEROSTRUCTURES, FROHLICH INTERACTION, OPTICAL
<> PHONONS, SUPERLATTICES, MODES, POLARIZABILITY, REDUCTION,
<> CRYSTALS, FIELD
<>
<> (126) TI: EFFECT OF BULK DISPERSION ON THE ELECTRON OPTICAL-PHONON
<> INTERACTION IN A SINGLE-QUANTUM-WELL
<> AU: CONSTANTINOU_NC, RIDLEY_BK
<> NA: UNIV ESSEX,DEPT PHYS,COLCHESTER CO4 3SQ,ESSEX,ENGLAND
<> JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1994, Vol.49, No.24,
<> pp.17065-17071
<> IS: 0163-1829
<> AB: The interaction of electrons with GaAs optical phonons is
<> investigated for a single GaAs/AlAs quantum well using the
<> hybrid model of optical phonons, which incorporates bulk-mode
<> dispersion. We predict resonances in the individual hybrid
<> scattering rates as a function of well width corresponding to
<> wave vectors where the modes anticross. Nevertheless, although
<> the physics is quite different, we find that the total
<> scattering rate is insensitive to the value of the bulk
<> dispersion, and is given to an excellent approximation by the
<> dielectric continuum model, for both intrasubband and
<> intersubband scattering processes. We conclude, in accord with
<> recent results of lattice dynamics, that for the evaluation of
<> scattering rates, the dielectric continuum model provides a
<> very good approximation.
<> KP: GAAS-ALAS SUPERLATTICES, SEMICONDUCTOR HETEROSTRUCTURES, RAMAN-
<> SCATTERING, CONFINED LO, MODES, SYSTEMS, REDUCTION
<>
<> (127) TI: GUIDED ACOUSTIC PHONONS IN QUANTUM WIRES - THEORY OF PHONON
<> FIBER
<> AU: NISHIGUCHI_N
<> NA: HOKKAIDO UNIV,DEPT ENGN SCI,SAPPORO,HOKKAIDO 060,JAPAN
<> JN: JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS SHORT
<> NOTES & REVIEW PAPERS, 1994, Vol.33, No.5B, pp.2852-2858
<> IS: 0021-4922
<> AB: Acoustic phonon modes confined to a GaAs cylindrical quantum
<> wire within AlAs are analytically investigated within the
<> context of an elastic continuum model. Elastic properties are
<> assumed to be isotropic for both materials for mathematical
<> convenience. The displacement vector is expressed by the scalar
<> potential and two vector potentials. The confined acoustic
<> phonon modes are classified into three types according to the
<> rotational symmetry of the potential functions: dilatational,
<> torsional, and flexural modes. Dispersion curves of the modes
<> show phonon subband structures with finite cutoff frequencies
<> due to confinement of wave, in lateral directions. The density
<> of the confined phonon modes accordingly appears as
<> staircaselike structures.
<> KP: CONFINED LO PHONONS, WELL WIRES, SCATTERING RATES, MODES,
<> SEMICONDUCTOR, ELECTRONS, MOBILITY, GAAS
<> WA: CONFINED ACOUSTIC PHONON, QUANTUM WIRE, PHONON SUBBAND, PHONON
<> FIBER, PHONON DEVICE
<>
<> (128) TI: HOT-ELECTRON RELAXATION DYNAMICS IN QUANTUM WIRES
<> AU: GASKA_R, MICKEVICIUS_R, MITIN_V, STROSCIO_MA, IAFRATE_GJ
<> NA: WAYNE STATE UNIV,DEPT ELECT & COMP ENGN,DETROIT,MI,48202
<> USA,RES OFF,RES TRIANGLE PK,NC,27709
<> SCI RES ASSOCIATES INC,GLASTONBURY,CT,06033
<> JN: JOURNAL OF APPLIED PHYSICS, 1994, Vol.76, No.2, pp.1021-1028
<> IS: 0021-8979
<> AB: Monte Carlo simulations of hot nonequilibrium electron
<> relaxation in rectangular GaAs quantum wires of different cross
<> sections are carried out. The simulations demonstrate that the
<> initial stage of hot-electron cooling dynamics is determined by
<> cascade emission of optical phonons and exhibits strong
<> dependence on the excitation energy. The second (slow)
<> relaxation stage is controlled by strongly inelastic electron
<> interactions with acoustic phonons as well as by nonequilibrium
<> (hot) optical phonons. The relaxation times obtained in our
<> simulations are in good agreement with the results of recent
<> luminescence experiments. At low electron concentrations where
<> hot phonon effects are negligible the cascade emission of
<> optical phonons may lead to the overcooling of the electron
<> system to temperature below the lattice temperature. These
<> electrons then slowly (during tens of picoseconds) relax to
<> equilibrium due to the interaction with acoustic phonons. At
<> certain excitation energies strong intersubband electron
<> scattering by optical phonons leads to electron redistribution
<> among subbands and intersubband population inversions. If the
<> electron concentration exceeds 10(5) cm-1, hot phonon effects
<> come into play. In contrast to bulk materials and quantum
<> wells, hot phonon effects in quantum wires exhibit strong
<> dependence on the initial broadening of the energy distribution
<> of the electrons. The very initial electron gas relaxation
<> stage in quantum wires is faster in the presence of hot
<> phonons, while for t>0.5 ps the hot phonon thermalization time
<> defines the characteristic electron cooling time.
<> KP: HIGH-FIELD TRANSPORT, PHONON INTERACTION, CARRIER DYNAMICS,
<> ENERGY-LOSS, SCATTERING, RATES
<>
<> (129) TI: EFFECTS OF ELECTRON-INTERFACE-PHONON INTERACTIONS ON
<> INTERACTIONS BETWEEN ELECTRONS IN DOUBLE-HETEROSTRUCTURES
<> AU: WANG_X, MAHAN_GD
<> NA: INNER MONGOLIA UNIV,DEPT PHYS,HOHHOT 010021,PEOPLES R CHINA
<> UNIV TENNESSEE,DEPT PHYS & ASTRON,KNOXVILLE,TN,37996
<> JN: ZEITSCHRIFT FUR PHYSIK B-CONDENSED MATTER, 1994, Vol.95, No.2,
<> pp.225-229
<> IS: 0722-3277
<> AB: Effects of electron-interface-phonon interaction on the
<> interaction between electrons in double heterostructures are
<> considered. It is found that the interaction potential between
<> electrons caused by each of four interface-phonon modes is
<> different. For electrons moving at the two interfaces of double
<> heterostructure, the interaction energies of the electrons
<> produced by the interaction with antisymmetric modes are
<> positive which indicate that the forces between electrons are
<> repulsive. The interaction energies caused by interaction with
<> symmetric modes are negative and the forces are attractive. The
<> resultant of the forces are attractive and become larger when
<> the width of potential barrier decreases for InAs/GaSb/InAs
<> double heterostructure.
<> KP: GAAS-ALAS SUPERLATTICES, QUANTUM-WELL, FROHLICH INTERACTION,
<> SUPERCONDUCTIVITY, POLARON, RESONANCE, MODEL
<>
<> (130) TI: ELECTRON-OPTICAL PHONON-SCATTERING RATES IN 2D STRUCTURES -
<> EFFECTS OF INDEPENDENT ELECTRON AND PHONON CONFINEMENT
<> AU: POZELA_J, BUTKUS_G, JUCIENE_V
<> NA: ICSC WORLD LAB,SEMICOND PHYS INST,GOSTAUTO 11,VILNIUS,LITHUANIA
<> JN: SEMICONDUCTOR SCIENCE AND TECHNOLOGY, 1994, Vol.9, No.8,
<> pp.1480-1483
<> IS: 0268-1242
<> AB: Two-dimensional structures with different thicknesses of
<> confined optical phonon and electron quantum wells are
<> proposed. The confined electron-polar optical phonon scattering
<> rates in these structures when an electron quantum well is
<> localized inside a phonon one are calculated. The independent
<> electron and phonon confinement allows the scattering rates by
<> confined and interface phonons to change significantly. The
<> effect of independent electron and phonon confinement is
<> demonstrated for an AlAs/GaAs/AlAs structure.
<> KP: QUANTUM-WELLS, SUPERLATTICES, HETEROSTRUCTURES
<>
<> (131) TI: ELECTRON-ACOUSTIC-PHONON SCATTERING RATES IN RECTANGULAR
<> QUANTUM WIRES
<> AU: YU_SG, KIM_KW, STROSCIO_MA, IAFRATE_GJ, BALLATO_A
<> NA: N CAROLINA STATE UNIV,DEPT ELECT & COMP ENGN,RALEIGH,NC,27695
<> USA,RES OFF,RES TRIANGLE PK,NC,27709
<> USA,RES LAB,ELECTR & POWER SOURCES DIRECTORATE,FT
<> MONMOUTH,NJ,07703
<> JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1994, Vol.50, No.3,
<> pp.1733-1738
<> IS: 0163-1829
<> AB: Electron-acoustic-phonon scattering in a rectangular quantum
<> wire is studied. The Hamiltonian describing the deformation-
<> potential interaction of confined acoustic phonons with
<> carriers is derived by quantizing the appropriate,
<> experimentally verified approximate compressional acoustic-
<> phonon modes in a free-standing rectangular quantum wire. The
<> scattering rate due to the deformation-potential interaction is
<> obtained for GaAs quantum wires with a range of cross-sectional
<> dimensions. The results demonstrate that a proper treatment of
<> confined acoustic phonons may be essential to correctly model
<> electron scattering rates at low energies in nanoscale
<> structures.
<> KP: HETEROSTRUCTURES, MODES, CARRIERS
<>
<> (132) TI: PHONON-ASSISTED GAMMA-X TRANSITION RATES IN TYPE-II
<> SUPERLATTICES
<> AU: ERDOGAN_MU, SANKARAN_V, KIM_KW, STROSCIO_MA, IAFRATE_GJ
<> NA: N CAROLINA STATE UNIV,DEPT ELECT & COMP ENGN,RALEIGH,NC,27695
<> USA,RES OFF,RES TRIANGLE PK,NC,27709
<> JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1994, Vol.50, No.4,
<> pp.2485-2491
<> IS: 0163-1829
<> AB: The GAMMA-X transition rate for electrons in type-II
<> superlattices is calculated for the case of optical-phonon
<> emission. The tight-binding method for electronic band
<> structure and the dielectric continuum model for phonons are
<> used. The relative strength of scattering due to different
<> phonon modes is examined for varying superlattice dimensions.
<> The scattering rate is highest when the energy separation
<> between the GAMMA and X levels is smallest, and decreases
<> quickly as the separation increases. It is found that the
<> strongest scattering rate is due to the emission of AlAs
<> confined modes. Changing of parity with layer thickness and its
<> effect on scattering are discussed.
<> KP: SHORT-PERIOD SUPERLATTICES, QUANTUM-WELLS, INTERSUBBAND
<> RELAXATION, ELECTRON, HETEROSTRUCTURES
<>
<> (133) TI: SIZE DEPENDENCE OF A MAGNETOPOLARON IN CYLINDRICAL QUANTUM
<> WIRES AT ARBITRARY MAGNETIC-FIELDS
<> AU: ZHOU_HY, GU_SW
<> NA: CCAST,WORLD LAB,BEIJING 100080,PEOPLES R CHINA
<> SHANGHAI JIAO TONG UNIV,INST CONDENSED MATTER PHYS,DEPT APPL
<> PHYS,SHANGHAI 200030,PEOPLES R CHINA
<> JN: ZEITSCHRIFT FUR PHYSIK B-CONDENSED MATTER, 1994, Vol.95, No.3,
<> pp.317-320
<> IS: 0722-3277
<> AB: With the use of variational method to solve the effective mass
<> equation, we have studied the cyclotron resonance of a
<> magnetopolaron in cylindrical quantum wires at arbitrary
<> magnetic fields. The interaction of the electron with surface-
<> optical (SO) phonons is used. Having calculated the ground
<> state energy and the excited state energy of the
<> magnetopolaron, we obtain the hybrid frequency of the
<> magnetopolaron in quantum wires.
<> KP: CYCLOTRON-RESONANCE, WELL WIRES, ENERGY, ELECTRONS,
<> HETEROSTRUCTURES, SPECTRA, PHONONS, SINGLE
<>
<> (134) TI: INTERACTION HAMILTONIAN BETWEEN AN ELECTRON AND INTERFACE
<> OPTICAL PHONONS IN A 4-LAYER HETEROSTRUCTURE
<> AU: SHI_JJ, PAN_SH
<> NA: HENAN NORMAL UNIV,DEPT PHYS,XINXIANG 453002,PEOPLES R CHINA
<> CHINA CTR ADV SCI & TECHNOL,WORLD LAB,BEIJING 100080,PEOPLES R
<> CHINA
<> ACAD SINICA,INST PHYS,BEIJING 100080,PEOPLES R CHINA
<> JN: CHINESE PHYSICS LETTERS, 1994, Vol.11, No.7, pp.439-442
<> IS: 0256-307X
<> AB: The interaction Frolich-like Hamiltonian between an electron
<> and interface optical phonons in a four-layer heterostructure
<> (FLHS) is obtained by means of the orthonormal eigenmodes of
<> interface optical phonons given recently. The electron-phonon
<> coupling functions and their plots for a FLHS and its special
<> cases, an asymmetric trilayer heterostructure (asymmetric
<> single quantum well) and a step quantum well, are given and
<> discussed. We find that the three branches of higher-
<> frequencies are more important for the electron-phonon
<> interaction than the other three in the six branches of
<> interface modes in a FLHS. Moreover, we also find that the
<> situation in an asymmetric trilayer heterostructure is similar
<> to that of a FLHS.
<>
<> (135) TI: BULK AND INTERFACE POLARONS IN QUANTUM WIRES AND DOTS
<> AU: KLIMIN_SN, POKATILOV_EP, FOMIN_VM
<> NA: MOLDAVIAN STATE UNIV,DEPT THEORET PHYS,MATEEVICI 60,KISHINEV
<> 277009,MOLDOVA
<> MOLDAVIAN STATE UNIV,PHYS MULTILAYER STRUCT LAB,KISHINEV
<> 277009,MOLDOVA
<> JN: PHYSICA STATUS SOLIDI B-BASIC RESEARCH, 1994, Vol.184, No.2,
<> pp.373-383
<> IS: 0370-1972
<> AB: The vibrational modes of inertial polarization in the
<> multilayer wire-like and dot-like structures are determined.
<> The bulk confinement modes and the interface ones are separated
<> exactly by a unitary transformation, various additional
<> boundary conditions for the inertial polarization vector being
<> taken into account. The Hamiltonian of the electron-phonon
<> interaction is deduced. The polaron ground state energy as well
<> as the effective mass in the cylindrical quantum wire and
<> polaronic shift of electron energy levels in the spherical
<> quantum dot are calculated.
<> KP: ELECTRON-PHONON INTERACTION, OPTICAL PHONONS, SEMICONDUCTOR
<> MICROCRYSTALS, CONFINED LO, SELF-ENERGY, WELL WIRES, BOXES,
<> HETEROSTRUCTURES, SUPERLATTICES, SCATTERING
<>
<> (136) TI: FREE-CARRIER ABSORPTION IN QUANTUM-WELL STRUCTURES DUE TO
<> CONFINED AND INTERFACE OPTICAL PHONONS
<> AU: BHAT_JS, MULIMANI_BG, KUBAKADDI_SS
<> NA: SDM COLL ENGN,DEPT PHYS,DHARWAR 580002,INDIA
<> KARNATAK UNIV,DEPT PHYS,DHARWAR 580003,KARNATAKA,INDIA
<> JN: PHYSICA STATUS SOLIDI B-BASIC RESEARCH, 1994, Vol.182, No.1,
<> pp.119-131
<> IS: 0370-1972
<> AB: A theory of free carrier absorption in quantum wells when
<> electrons are scattered by confined LO phonons described by the
<> Huang and Zhu model, Fuchs-Kliewer slab modes, and Ridley's
<> guided mode models is given. The effect of interface phonon
<> modes on free carrier absorption is also studied. Numerical
<> results for frequency and well width dependence are given for
<> parameters characteristic of the GaAs/AlAs quantum well. A
<> comparison is made with the calculations based on a bulk
<> description of phonons.
<> KP: QUANTIZING MAGNETIC-FIELD, SCATTERING RATES, DOUBLE
<> HETEROSTRUCTURES, ELECTRIC-FIELD, INTERSUBBAND TRANSITIONS,
<> FROHLICH INTERACTION, SUPERLATTICES, GAAS, MODES, ALAS
<>
<> (137) TI: SPECTRUM OF AN ELECTRON LOCALIZED BY ELECTROSTATIC IMAGE FORCES
<> IN THIN SEMICONDUCTOR LAYERS
<> AU: TKACH_M, HOLOVATSKY_V, VOITSEKHIVSKA_O
<> NA: STATE UNIV CHERNIVTSY,DEPT THEORET PHYS,KOTSIUBYNSKI 2,274012
<> CHERNOVTSY,UKRAINE
<> JN: PHYSICA STATUS SOLIDI B-BASIC RESEARCH, 1994, Vol.182, No.1,
<> pp.69-78
<> IS: 0370-1972
<> AB: The spectrum of an electron confined in a layer with the
<> dielectric constant epsilon embedded between two media with
<> larger (epsilon<> <> epsilon) and smaller (epsilon< < epsilon)
<> values of the dielectric constant is calculated. The dependence
<> of the spectrum on the layer thickness and on the ratio between
<> the dielectric constants of the layer and the media is
<> calculated. It is shown that if the crystal thickness
<> increases, the whole spectrum of electrons shifts into the
<> region of negative energies and becomes quasi-hydrogenic there.
<> KP: SURFACE PHONON-POLARITONS, BILAYER SYSTEMS, ENERGY
<>
<> (138) TI: PHONON-ASSISTED TUNNELING FROM A 2-DIMENSIONAL EMITTER STATE
<> AU: TURLEY_PJ, TEITSWORTH_SW
<> NA: DUKE UNIV,DEPT PHYS,BOX 90305,DURHAM,NC,27708
<> JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1994, Vol.50, No.12,
<> pp.8423-8432
<> IS: 0163-1829
<> AB: We present a theory of phonon-assisted tunneling in GaAs/AlAs
<> double-barrier structures, which. treats the electrons in the
<> emitter as a two-dimensional electron gas. A complete set of
<> confined and interface optical-phonon modes is calculated using
<> a dielectric-continuum model, and we derive a general
<> expression for the electron-phonon Hamiltonian valid for all
<> optical-phonon modes in an arbitrary heterostructure. The
<> electronic wave functions relevant to phonon-assisted tunneling
<> are found by self-consistently solving the Schrodinger and
<> Poisson equations in both the well and the emitter. Five
<> different phonon modes are predicted to dominate the phonon-
<> assisted tunneling current: three LO-like interface modes, the
<> half-space modes in the emitter, and the confined modes in the
<> well.
<> KP: DOUBLE-BARRIER STRUCTURES, ELECTRONIC POLARIZABILITY,
<> SCATTERING RATES, OPTICAL PHONONS, VALLEY CURRENT, DIODES,
<> HETEROSTRUCTURES, SUPERLATTICES, SYSTEMS, EMISSION
<>
<> (139) TI: EFFICIENT CALCULATION OF THE SCATTERING RATES IN VALENCE-BAND
<> QUANTUM-WELLS
<> AU: AFZALIKUSHAA_A, HADDAD_GI
<> NA: UNIV MICHIGAN,DEPT ELECT ENGN & COMP SCI,SOLID STATE ELECTR
<> LAB,ANN ARBOR,MI,48109
<> JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1994, Vol.50, No.11,
<> pp.7701-7707
<> IS: 0163-1829
<> AB: An effective approach for calculating the (phonon) scattering
<> rate in valence-band quantum wells is presented. The valence-
<> subband structure and the wave functions are obtained using the
<> multiband effective-mass approximation. The subband structure
<> is modeled by piecewise second-order polynomials. while its
<> anisotropy is neglected. The effect of the central-cell
<> symmetry is incorporated in the calculation by effectively
<> including the overlap integral in the transition probability
<> given by the Fermi golden rule. For a valence-band quantum
<> well, the relaxation rates due to the polar LO-phonon-,
<> nonpolar LO-phonon-, and LA-phonon-scattering mechanisms at
<> zero temperature are calculated. Due to the higher density of
<> states in valence-band quantum wells, the calculated scattering
<> rates are generally higher than the rates in similar structures
<> based on conduction-band quantum wells.
<> KP: OPTICAL-PHONON INTERACTION, ELECTRON, TRANSPORT,
<> HETEROSTRUCTURES, RELAXATION, SINGLE, HOLES
<>
<> (140) TI: POLAR OPTICAL PHONONS AT SEMICONDUCTOR INTERFACES
<> AU: CHUBYKALO_A, VELASCO_VR, GARCIAMOLINER_F
<> NA: CSIC,INST CIENCIA MAT,SERRANO 123,E-28006 MADRID,SPAIN
<> CSIC,INST CIENCIA MAT,E-28006 MADRID,SPAIN
<> JN: SURFACE SCIENCE, 1994, Vol.319, No.1-2, pp.184-192
<> IS: 0039-6028
<> AB: We study long wave polar optical modes at semiconductor
<> surfaces (GaAs) and interfaces (GaAs/ALAs). We have considered
<> also the cases in which the surface or interface is kept at a
<> fixed electrostatic potential. The spectrum of excitations then
<> shows significant differences. The existence of localized and
<> resonant modes has been obtained by studying the spectral
<> strength through the surface Green function matching (SGFM)
<> method.
<> KP: ENERGY-LOSS SPECTRUM, QUANTUM-WELLS, GAAS/ALAS SUPERLATTICES,
<> LAYERED SYSTEMS, SURFACE, MODES, GAAS, EXCITATIONS, SCATTERING,
<> GAAS(110)
<>
<> (141) TI: CONTINUUM MODEL OF THE OPTICAL MODES OF VIBRATION OF AN IONIC-
<> CRYSTAL SLAB
<> AU: RIDLEY_BK, ALDOSSARY_O, CONSTANTINOU_NC, BABIKER_M
<> NA: UNIV ESSEX,DEPT PHYS,WIVENHOE PK,COLCHESTER CO4
<> 3SQ,ESSEX,ENGLAND
<> JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1994, Vol.50, No.16,
<> pp.11701-11709
<> IS: 0163-1829
<> AB: Optical vibrations of a thin ionic slab are described by a
<> macroscopic theory involving the hybridization of LO, TO, and
<> interface-polariton modes. The resultant modes are triple
<> hybrids, which satisfy both elastic and electromagnetic
<> boundary conditions at the two surfaces. Analytic expressions
<> are derived for the relative ionic displacements and related
<> electric fields, and for the dispersion relations, assuming
<> elastic isotropy and neglecting retardation effects. Comparison
<> of mode patterns with those obtained by Fuchs and Kliewer, who
<> used electromagnetic boundary conditions only, show that Fuchs-
<> Kliewer modes are a good approximation to the system of the
<> triple-hybrid modes our theory describes.
<> KP: ELECTRON-PHONON INTERACTION, GAAS-ALAS SUPERLATTICES, QUANTUM-
<> WELLS, DOUBLE HETEROSTRUCTURES, FROHLICH INTERACTION,
<> DISPERSION, SCATTERING
<>
<> (142) TI: POLARONIC EFFECT ON THE ELECTRON-ENERGY SPECTRUM IN A QUANTUM-
<> WELL
<> AU: ZHENG_RS, BAN_SL, LIANG_XX
<> NA: INNER MONGOLIA UNIV,DEPT PHYS,HOHHOT 010021,PEOPLES R CHINA
<> CHINA CTR ADV SCI & TECHNOL,WORLD LAB,BEIJING 100080,PEOPLES R
<> CHINA
<> JN: JOURNAL OF PHYSICS-CONDENSED MATTER, 1994, Vol.6, No.47,
<> pp.10307-10316
<> IS: 0953-8984
<> AB: A general analytical expression for the electron energy
<> spectrum and the polaron binding energy for different
<> electronic subband bound states in a quantum well (QW) is
<> presented. The effects of the electron-optical-phonon
<> interaction, the finite confinement potential, the difference
<> in the electronic effective masses across the interface, and
<> the electron subband state are considered in this paper. The
<> correct three-dimensional and two-dimensional results are given
<> as the limit cases when the well width varies from infinity to
<> zero. The expression is numerically applied to the GaAs/AlxGa1-
<> xAs QWS with several different aluminium concentrations x. Some
<> properties of the polaron are discussed.
<> KP: CYCLOTRON-RESONANCE SPECTRUM, OPTICAL-PHONON INTERACTION,
<> DOUBLE HETEROSTRUCTURES, EFFECTIVE MASS, GROUND-STATE, MODES,
<> GAAS, SUPERLATTICES, CRYSTALS, INTERFACE
<>
<> (143) TI: RAMAN-SCATTERING FROM INTERFACE PHONONS IN GAINP/ALINP
<> SUPERLATTICE
<> AU: OCHIAI_S, TANOKURA_Y, SEKINE_T, KIKUCHI_A, KANEKO_Y, KISHINO_K
<> NA: SOPHIA UNIV,FAC SCI & TECHNOL,DEPT PHYS,CHIYODA KU,7-1 KIOI
<> CHO,TOKYO 102,JAPAN
<> SOPHIA UNIV,FAC SCI & TECHNOL,DEPT ELECT & ELECTR ENGN,CHIYODA
<> KU,TOKYO 102,JAPAN
<> JN: JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN, 1994, Vol.63, No.11,
<> pp.4244-4248
<> IS: 0031-9015
<> AB: Measurements of Raman scattering were performed on ternary
<> alloy superlattices GaInP/AlInP grown by gas-source molecular
<> beam epitaxy. We observed interface phonons whose frequencies
<> are explained in terms of an electrostatic continuum model
<> using the optical phonons of AlInP and GaInP bulk alloys. The
<> Raman intensities of the interface phonons are enhanced when
<> the incident photon energy is close to the exciton energy in
<> the GaInP quantum wells and to the band gap energy in the
<> AlInP. We measured Raman spectra of AlGaInP quaternary alloy,
<> which have the same composition on a standpoint of average
<> crystal structure, and compare it with the spectra of the
<> superlattice.
<> KP: MOLECULAR-BEAM-EPITAXY, GAAS-ALAS SUPERLATTICES,
<> HETEROSTRUCTURE, GAINP
<> WA: GAINP/ALINP TERNARY ALLOY SUPERLATTICES, INTERFACE PHONONS,
<> ELECTROSTATIC CONTINUUM MODEL, RESONANT RAMAN EFFECT, ALGAINP
<> QUATERNARY ALLOY
<>
<> (144) TI: RESONANT-TUNNELING - FROM MODEL HAMILTONIAN TO MODERN
<> ELECTRONIC DEVICES
<> AU: CHAO_KA, WILLANDER_M, GALPERIN_YM
<> NA: NORWEGIAN INST TECHNOL,FAC MATH & PHYS,DIV PHYS,N-7034
<> TRONDHEIM,NORWAY
<> LINKOPING UNIV,DEPT PHYS & MEASUREMENT TECHNOL,S-58183
<> LINKOPING,SWEDEN
<> UNIV OSLO,DEPT PHYS,N-0316 OSLO 3,NORWAY
<> AF IOFFE PHYS TECH INST,ST PETERSBURG 194021,RUSSIA
<> JN: PHYSICA SCRIPTA, 1994, Vol.54, pp.119-122
<> IS: 0281-1847
<> AB: The single-electron theory of resonant-tunneling through a
<> double-barrier structure with perfect interfaces has been
<> reviewed, and the future direction of theoretical development
<> including the electron-electron interaction and rough
<> interfaces is outlined. The theoretical understanding of this
<> system reveals its potential application to quantum electronic
<> devices.
<> KP: DOUBLE-BARRIER, PHONON INTERACTION, HETEROSTRUCTURES, DIODES,
<> CONDUCTANCE, BISTABILITY, TRANSPORT, VOLTAGE
<>
<> (145) TI: HOT-ELECTRON ENERGY AND MOMENTUM RELAXATION IN GAAS/ALAS AND
<> GAAS/GA1-XALXAS MULTIPLE-QUANTUM WELLS
<> AU: OZTURK_E, STRAW_A, BALKAN_N
<> NA: UNIV ESSEX,DEPT PHYS,WIVENHOE PK,COLCHESTER CO4
<> 3SQ,ESSEX,ENGLAND
<> JN: SUPERLATTICES AND MICROSTRUCTURES, 1994, Vol.15, No.2, pp.165-
<> 169
<> IS: 0749-6036
<> AB: Experimental results on high electric field longitudinal
<> transport in GaAs/AlAs and GaAs/Ga1-xAlxAs multiple quantum
<> wells (MQW) are presented and compared with the prediction of a
<> dielectric continuum model. We draw from our experiments the
<> following four conclusions.
<> (i) In GaAs/Ga1-xAlxAs systems the dominant energy and momentum
<> relaxation mechanism is through scattering with GaAs-modes.
<> (ii) However, in GaAs/AlAs systems the AlAs interface mode is
<> dominant in relaxing the energy and momentum of the quantum
<> well electrons.
<> (iii) The hot electron momentum relaxation as obtained from the
<> high-field drift velocity experiments is strongly affected by
<> the production of hot phonons as expected from a model
<> involving a non-drifting hot phonon distribution.
<> (iv) The importance of the AlAs interface mode in GaAs/Ga1-
<> xAlxAs MQW is not the result of the intrinsic scattering rate
<> but related to its shorter lifetime, compared to GaAs modes.
<> KP: HIGH-FIELD TRANSPORT, POLAR SEMICONDUCTORS, OPTICAL PHONONS,
<> SCATTERING, HETEROSTRUCTURES, RATES
<>
<> (146) TI: CYCLOTRON-RESONANCE OF 2-DIMENSIONAL INTERFACE POLARONS
<> AU: BAN_SL, LIANG_XX, ZHENG_RS
<> NA: INNER MONGOLIA UNIV,DEPT PHYS,SOLID STATE PHYS LAB,HOHHOT
<> 010021,PEOPLES R CHINA
<> CHINA CTR ADV SCI & TECHNOL,WORLD LAB,BEIJING 100080,PEOPLES R
<> CHINA
<> JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1995, Vol.51, No.4,
<> pp.2351-2356
<> IS: 0163-1829
<> KP: OPTICAL-PHONON INTERACTION, SELF-TRAPPING ENERGY, SEMICONDUCTOR
<> SUPERLATTICES, CRYSTALS, MASS, HETEROJUNCTIONS
<>
<> (147) TI: ELECTRON-OPTICAL PHONON COUPLING IN DOUBLE-BARRIER QUANTUM-WELL
<> STRUCTURE
<> AU: KACZMAREK_E
<> NA: POLISH ACAD SCI,INST PHYS,AL LOTNIKOW 32-46,PL-02668
<> WARSAW,POLAND
<> JN: ACTA PHYSICA POLONICA A, 1995, Vol.87, No.1, pp.233-236
<> IS: 0587-4246
<> AB: The electron-LO phonon coupling constant for double-barrier
<> quantum well structure was calculated using the Frohlich model
<> of the electron-phonon interaction and assuming coupling of the
<> confined electron with bulk LO phonon mode. Magnitude of the
<> Huang-Rhys factor g and possibility of detecting of phonon
<> replicas in the resonant tunneling current are discussed for
<> GaAs-AlxGa1-xAs and CdTe based structures.
<> KP: DOUBLE HETEROSTRUCTURES
<>
<> (148) TI: ELECTRON RELAXATION BY INTERFACE-PHONON MODES IN QUANTUM DOTS
<> AU: DELACRUZ_RM
<> NA: UNIV COMPLUTENSE MADRID,FAC CIENCIAS FIS,DEPT FIS MAT,E-28040
<> MADRID,SPAIN
<> JN: SUPERLATTICES AND MICROSTRUCTURES, 1994, Vol.16, No.4, pp.427-
<> 431
<> IS: 0749-6036
<> AB: The role of interface phonon modes in electron relaxation
<> processes in a GaAs quantum dot which is free standing in
<> vacuum is investigated. For this, the electron scattering rates
<> by interface phonons are calculated using an electron-phonon
<> interaction Hamiltonian derived in the framework of the
<> dielectric continuum model. By comparing the relaxation times
<> to the radiative recombination lifetime of electrons and holes
<> in their ground states, it is established that electron
<> relaxation via interface phonon emission is significant in the
<> radiative decay processes along with other relaxation
<> mechanisms via longitudinal optical and longitudinal acoustic
<> phonon emission. Different selection rules are obtained if the
<> interface phonon mode involved in the scattering processes is
<> symmetric or antisymmetric.
<> KP: SCATTERING, WIRES
<>
<> (149) TI: ELECTRON ACOUSTIC-PHONON SCATTERING RATES IN CYLINDRICAL
<> QUANTUM WIRES
<> AU: YU_SG, KIM_KW, STROSCIO_MA, IAFRATE_GJ
<> NA: N CAROLINA STATE UNIV,DEPT ELECT & COMP ENGN,RALEIGH,NC,27695
<> USA,RES OFF,RES TRIANGLE PK,NC,27709
<> N CAROLINA STATE UNIV,DEPT PHYS,RALEIGH,NC,27695
<> JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1995, Vol.51, No.7,
<> pp.4695-4698
<> IS: 0163-1829
<> DT: Note
<> KP: BRILLOUIN-SCATTERING, RAMAN-SCATTERING, FILMS, MODES
<>
<> (150) TI: SELF-ENERGY OF A MAGNETOPOLARON AT THE INTERFACE OF POLAR
<> CRYSTALS
<> AU: WEI_BH, YU_KW
<> NA: S CHINA UNIV TECHNOL,DEPT APPL PHYS,CANTON 510641,PEOPLES R
<> CHINA
<> CHINESE UNIV HONG KONG,DEPT PHYS,SHA TIN,HONG KONG
<> ACAD SINICA,INT CTR MAT PHYS,SHENYANG 110015,PEOPLES R CHINA
<> JN: JOURNAL OF PHYSICS-CONDENSED MATTER, 1995, Vol.7, No.6,
<> pp.1059-1067
<> IS: 0953-8984
<> AB: The self-energy of an interface electron interacting with bulk
<> longitudinal-optical phonons as well as interface optical (IO)
<> phonons in a magnetic field of arbitrary strength is studied
<> using the Green function method. Our results show that the
<> absolute value \E(e-ph)((0))\ of the ground-state self-energy
<> of the electron is a rapidly increasing function of the
<> magnetic field in the weak-magnetic-field region, but \E(e-
<> ph)((0))\ is a slowly decreasing function of the magnetic field
<> beyond a critical magnetic field B-c. For the excited states,
<> \E(e-ph)((n))\(n greater than or equal to 1) is an increasing
<> function of the magnetic field in the pre-resonant region,
<> while E(e-ph)((n)) is a positive and decreasing function of the
<> magnetic field beyond the resonant region. Numerical results
<> show that the electron-IO phonon interaction contributes only
<> when the mean distance of the polaron from the interface is
<> small and in the extremely-weak-magnetic-field region.
<> KP: CYCLOTRON-RESONANCE SPECTRUM, OPTICAL-PHONON INTERACTION,
<> MAGNETIC-FIELD, 2 DIMENSIONS, QUANTUM-WELL
<>
<> (151) TI: THEORY OF ONE-PHONON RAMAN-SCATTERING IN SEMICONDUCTOR
<> MICROCRYSTALLITES
<> AU: CHAMBERLAIN_MP, TRALLEROGINER_C, CARDONA_M
<> NA: MAX PLANCK INST FESTKORPERFORSCHUNG,HEISENBERGSTR 1,D-70569
<> STUTTGART,GERMANY
<> HAVANA UNIV,DEPT THEORET PHYS,VEDAO 10400,CUBA
<> JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1995, Vol.51, No.3,
<> pp.1680-1693
<> IS: 0163-1829
<> KP: SIZE DEPENDENCE, OPTICAL MODES, QUANTUM-WELLS, GLASS MATRIX,
<> ELECTRON, SPECTROSCOPY, SYSTEMS, CDSE
<>
<> (152) TI: POLAR OPTICAL OSCILLATIONS IN QUANTUM WIRES AND FREESTANDING
<> WIRES - THE ELECTRON-PHONON INTERACTION HAMILTONIAN
<> AU: COMAS_F, CANTARERO_A, TRALLEROGINER_C, MOSHINSKY_M
<> NA: UNIV VALENCIA,DEPT FIS APLICADA,DR MOLINER 50,E-46100
<> BURJASSOT,SPAIN
<> MAX PLANCK INST FESTKORPERFORSCH,D-70569 STUTTGART,GERMANY
<> UNIV HAVANA,DEPT THEORET PHYS,HAVANA,CUBA
<> UNIV NACL AUTONOMA MEXICO,INST FIS,MEXICO CITY 01000,DF,MEXICO
<> JN: JOURNAL OF PHYSICS-CONDENSED MATTER, 1995, Vol.7, No.9,
<> pp.1789-1805
<> IS: 0953-8984
<> AB: By applying a phenomenological theory for long-wavelength polar
<> optical oscillations to mesoscopic layered semiconductor
<> structures, we calculate the normal modes of a quantum wire and
<> of a free-standing wire. the cylindrical geometry is adopted
<> with circular cross-section of radius r(0). The displacement
<> held u and the electric potential phi are calculated for the
<> different modes, as well as the dispersion relation curves. The
<> case of the GaAs/AlAs structure is analysed. We limit ourselves
<> to the study of oscillations perpendicular to the wire axis.
<> The electron-phonon interaction Hamiltonian is derived for the
<> present problem using the second-quantization formalism.
<> KP: GAAS-ALAS SUPERLATTICES, SEMICONDUCTOR SUPERLATTICES, GAAS/ALAS
<> SUPERLATTICES, DOUBLE HETEROSTRUCTURES, RAMAN-SCATTERING,
<> LATTICE-DYNAMICS, CONFINED LO, MODES, SYSTEMS, WELLS
<>
<> (153) TI: SPECTRUM POLARIZATION PHONONS IN THE 3-LAYER SPHERIC
<> HETEROSYSTEM
<> LA: Russian
<> AU: TKACH_NV
<> NA: Y FEDKOVICH STATE UNIV,CHERNOVTSY,UKRAINE
<> JN: FIZIKA TVERDOGO TELA, 1994, Vol.36, No.11, pp.3222-3232
<> IS: 0367-3294
<> KP: ELECTRON
<>
<> (154) TI: THE INFLUENCE OF CONFINED OPTICAL PHONONS ON EXCITONIC STATES
<> IN QUANTUM-WELL
<> LA: Ukrainian
<> AU: BOICHUK_VI, PAZJUK_RI
<> NA: I FRANKO PEDAG INST,34 FRANKO ST,DROGOBYCH 293720,UKRAINE
<> JN: UKRAINSKII FIZICHESKII ZHURNAL, 1994, Vol.39, No.2, pp.212-215
<> IS: 0503-1265
<> AB: The influence of confined optical phonons on shift and half -
<> width of exciton stripe absorption for Wannier-Mott exciton in
<> quantum well, which is the model of semiconductor film or
<> double semiconductor heterostructure, is studied. The problem
<> is salved by Green function method.
<> KP: LINEWIDTHS, ENERGY
<>
<> (155) TI: BALLISTIC PROPAGATION OF INTERFACE OPTICAL PHONONS
<> AU: SIRENKO_YM, STROSCIO_MA, KIM_KW, MITIN_V
<> NA: N CAROLINA STATE UNIV,DEPT ELECT & COMP ENGN,RALEIGH,NC,27695
<> USA,RES OFF,RES TRIANGLE PK,NC,27709
<> WAYNE STATE UNIV,DEPT ELECT & COMP ENGN,DETROIT,MI,48202
<> JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1995, Vol.51, No.15,
<> pp.9863-9866
<> IS: 0163-1829
<> KP: ELECTRON-HOLE TRANSPORT, LO PHONONS, GAAS, HETEROSTRUCTURES,
<> RAMAN, DIMENSIONALITY, SCATTERING, GENERATION, STATISTICS,
<> GAAS/ALAS
<>
<> (156) TI: RESONANT MAGNETOPOLARON EFFECT IN D- CENTERS IN QUANTUM-WELLS
<> AU: CHEN_R, BAJAJ_KK, CHENG_JP, MCCOMBE_BD
<> NA: EMORY UNIV,DEPT PHYS,ATLANTA,GA,30322
<> MIT,FRANCIS BITTER NATL MAGNET LAB,CAMBRIDGE,MA,02139
<> SUNY BUFFALO,DEPT PHYS & ASTRON,BUFFALO,NY,14260
<> JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1995, Vol.51, No.15,
<> pp.9825-9829
<> IS: 0163-1829
<> KP: 2-DIMENSIONAL D-CENTERS, HIGH MAGNETIC-FIELDS, CYCLOTRON-
<> RESONANCE, TRANSITION ENERGIES, STATES, GAAS
<>
<> (157) TI: CHEMICAL-COMPOSITION FLUCTUATIONS AT INTERFACES IN QUANTUM-WELL
<> STRUCTURES - EFFECT ON INTERFACE-PHONON MODES
<> AU: DUAN_WH, ZHU_JL, GU_BL, WANG_CY
<> NA: CHINA CTR ADV SCI & TECHNOL,CTR THEORET PHYS,WORLD LAB,POB
<> 8730,BEIJING 100080,PEOPLES R CHINA
<> TSING HUA UNIV,DEPT PHYS,BEIJING 100084,PEOPLES R CHINA
<> CENT IRON & STEEL RES INST,BEIJING 100081,PEOPLES R CHINA
<> JN: PHYSICS LETTERS A, 1995, Vol.200, No.3-4, pp.329-334
<> IS: 0375-9601
<> AB: On the basis of the dielectric continuum model, the optical
<> phonon modes and related dispersion relations in GaAs-Ga1-
<> xAlxAs quantum well structures with chemical composition
<> fluctuations at the interfaces are investigated. The dependence
<> of the modes on chemical composition fluctuations and their
<> symmetry is clearly demonstrated.
<> KP: SEMICONDUCTOR HETEROSTRUCTURES, ELECTRONIC POLARIZABILITY,
<> SCATTERING, EXCITONS, SINGLE, FIELD
<>
<> (158) TI: INFLUENCE OF OPTICAL PHONONS ON INTERFACE STATES OF THE
<> ELECTRON-PHONON SYSTEM
<> LA: Ukrainian
<> AU: BILYNSKII_IV, BOYCHUK_VI
<> NA: I FRANKO PEDAG INST,34 I FRANKO ST,DROGOBYCH 293720,UKRAINE
<> JN: UKRAINSKII FIZICHESKII ZHURNAL, 1994, Vol.39, No.3-4, pp.447-
<> 450
<> IS: 0503-1265
<> AB: The electron of an interface state, which interacts with volume
<> and interface optical phonons, is studied. The problem is
<> solved for different values of the constants of electron-phonon
<> interaction (g less than or equal to 1) and for the model
<> crystal CaAs/AlAs (g = 0,03). The dependence of both energy and
<> life-time of a polaron and excited states of the electron-
<> phonon system on the constant g and the distance of an electron
<> to the interface is obtained.
<>
<> (159) TI: ELECTRON-SCATTERING BY OPTICAL PHONONS IN 2D QUANTUM-WELLS WITH
<> INDEPENDENT CONFINEMENT OF ELECTRONS AND PHONONS
<> AU: POZELA_J, JUCIENE_V
<> NA: INT CTR SCI CULTURE,INST SEMICOND PHYS,VILNIUS 2600,LITHUANIA
<> INT CTR SCI CULTURE,WORLDWIDE LAB,VILNIUS 2600,LITHUANIA
<> JN: SEMICONDUCTORS, 1995, Vol.29, No.3, pp.236-241
<> IS: 1063-7826
<>
<> (160) TI: INFLUENCE OF INTERFACIAL DISORDER ON THE ELECTRON-ENERGY-LOSS
<> SPECTRUM OF ULTRA-THIN ALAS FILMS ON GAAS(001)
<> AU: GUYAUX_JL, LANGE_MD, SPORKEN_R, THIRY_PA, CAUDANO_R, SENET_P,
<> LAMBIN_P
<> NA: FAC UNIV NOTRE DAME PAIX,INTERDISCIPLINAIRE SPECT ELECTR
<> LAB,RUE BRUXELLES 61,B-5000 NAMUR,BELGIUM
<> FAC UNIV NOTRE DAME PAIX,LAB PHYS SOLIDE,B-5000 NAMUR,BELGIUM
<> JN: SURFACE SCIENCE, 1995, Vol.328, No.3, pp.L 566-L 570
<> IS: 0039-6028
<> DT: Letter
<> AB: High-resolution electron-energy-loss spectroscopy has been
<> applied to AlAs thin films grown by molecular beam epitaxy on
<> GaAs(001). The loss intensities show a dependence on overlayer
<> thickness that cannot be fully understood from the long-
<> wavelength dielectric properties of AlAs and GaAs, most
<> particularly below 12 monolayers of AlAs (3.4 nm), Microscopic
<> lattice-dynamics calculations of the surface dielectric
<> response of AlAs/GaAs heterostructures are in much better
<> agreement with the experimental observations when some cation
<> intermixing is assumed taking place around the interface.
<> KP: SUPERLATTICES, PHONONS, SURFACE, GAAS, DYNAMICS
<> WA: ALUMINUM ARSENIDE, ATOMISTIC DYNAMICS, ELECTRON ENERGY LOSS
<> SPECTROSCOPY, EPITAXY, GALLIUM ARSENIDE, SEMICONDUCTOR
<> SEMICONDUCTOR THIN FILMS
<>
<> (161) TI: FEMTOSECOND OPTICAL-ABSORPTION MEASUREMENTS OF ELECTRON-PHONON
<> SCATTERING GAAS QUANTUM-WELLS
<> AU: TURNER_K, ROTA_L, TAYLOR_RA, RYAN_JF, FOXON_CT
<> NA: UNIV OXFORD,DEPT PHYS,CLARENDON LAB,OXFORD OX1 3PU,ENGLAND
<> UNIV NOTTINGHAM,DEPT PHYS,NOTTINGHAM NG7 2RD,ENGLAND
<> JN: APPLIED PHYSICS LETTERS, 1995, Vol.66, No.23, pp.3188-3190
<> IS: 0003-6951
<> KP: INTERSUBBAND RELAXATION, RATES
<>
<> (162) TI: CARRIER CAPTURE PROCESSES IN SEMICONDUCTOR SUPERLATTICES DUE TO
<> EMISSION OF CONFINED PHONONS
<> AU: DEPAULA_AM, WEBER_G
<> NA: UNIV ESTADUAL CAMPINAS,INST FIS,CAIXA POSTAL 6165,BR-13083
<> CAMPINAS,BRAZIL
<> UNIV ESTADUAL CAMPINAS,INST FIS,BR-13083 CAMPINAS,BRAZIL
<> JN: JOURNAL OF APPLIED PHYSICS, 1995, Vol.77, No.12, pp.6306-6312
<> IS: 0021-8979
<> KP: QUANTUM-WELL STRUCTURES, RESONANT ELECTRON-CAPTURE,
<> INTERSUBBAND TRANSITIONS, DOUBLE HETEROSTRUCTURES, FROHLICH
<> INTERACTION, INTERFACE PHONONS, SCATTERING RATES, GRADED-INDEX,
<> ENERGY-LOSS, DYNAMICS
<>
<> (163) TI: CALCULATIONS OF HIGH-FREQUENCY RESPONSE OF 2-DIMENSIONAL HOT-
<> ELECTRONS IN GAAS QUANTUM-WELLS
<> AU: SARKAR_SK, GHOSH_PK, CHATTOPADHYAY_D
<> NA: DEEMED UNIV,BENGAL ENGN COLL,DEPT ELECTR & TELECOMMUN,HOWRAH
<> 711103,W BENGAL,INDIA
<> INST RADIOPHYS & ELECTR,CALCUTTA 700009,W BENGAL,INDIA
<> JN: JOURNAL OF APPLIED PHYSICS, 1995, Vol.78, No.1, pp.283-287
<> IS: 0021-8979
<> KP: OPTICAL-PHONON-SCATTERING, MOBILITY, HETEROSTRUCTURES,
<> SEMICONDUCTORS, GAS
<>
<> (164) TI: ELECTRON INTERFACE-PHONON INTERACTION AND SCATTERING IN
<> ASYMMETRIC SEMICONDUCTOR QUANTUM-WELL STRUCTURES
<> AU: SHI_JJ, PAN_SH
<> NA: HENAN NORMAL UNIV,DEPT PHYS,XINING 453002,PEOPLES R CHINA
<> CHINA CTR ADV SCI & TECHNOL,WORLD LAB,BEIJING 100080,PEOPLES R
<> CHINA
<> ACAD SINICA,INST PHYS,BEIJING 100080,PEOPLES R CHINA
<> JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1995, Vol.51, No.24,
<> pp.17681-17688
<> IS: 0163-1829
<> KP: POLAR CRYSTALS, DOUBLE HETEROSTRUCTURES, INTERSUBBAND
<> TRANSITIONS, MODES, GAAS, ALAS, SURFACE, FIELD
<>
<> (165) TI: PHONON BROADENING OF EXCITONS IN GAAS/ALXGA1-XAS QUANTUM-WELLS
<> AU: GAMMON_D, RUDIN_S, REINECKE_TL, KATZER_DS, KYONO_CS
<> NA: USN,RES LAB,WASHINGTON,DC,20375
<> USA,RES LAB,FT MONMOUTH,NJ,07703
<> JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1995, Vol.51, No.23,
<> pp.16785-16789
<> IS: 0163-1829
<> KP: SIZE DEPENDENCE, LINEWIDTHS, GAAS, SINGLE, ABSORPTION,
<> INTERFACES, RESONANCE, SPECTRA
<>
<> (166) TI: EFFECT OF STRONG ELECTRON-PHONON INTERACTIONS ON AN INTERFACE
<> POLARON
<> AU: LAI_ZY, GU_SW, AUYEUNG_TC, LI_WS, YEUNG_YY
<> NA: BOX 8594,HONG KONG,HONG KONG
<> SHANGHAI JIAO TONG UNIV,DEPT APPL PHYS,SHANGHAI 200030,PEOPLES
<> R CHINA
<> HONG KONG POLYTECH,DEPT APPL PHYS,HONG KONG,HONG KONG
<> HONG KONG POLYTECH,DEPT ELECTR ENGN,HONG KONG,HONG KONG
<> NANYANG TECHNOL UNIV,SCH ELECT & ELECTR ENGN,SINGAPORE
<> 2263,SINGAPORE
<> JN: COMMUNICATIONS IN THEORETICAL PHYSICS, 1995, Vol.23, No.4,
<> pp.395-404
<> IS: 0253-6102
<> AB: The present work deals with an electron interacting strongly
<> with both bulk longitudinal optical (LO) phonons and interface
<> (IF) optical phonons in which we adopt and generalize the
<> Tokuda's variational method for studying the interface polaron
<> properties in polar crystals at zero temperature. In our
<> approach, we can reduce the Hamiltonian equation of the system
<> to a pair of integro-differential equations in two variational
<> parameters of the. electron wavefunction from which we can
<> calculate various physical properties of an interface polaron
<> including the ground state energy, average numbers of
<> interacting phonons, the average distance from the interface
<> and the anisotropic effective masses of the interface polaron.
<> Numerical results are obtained explicitly for LiF crystal
<> interfaced with NaF crystal as well as other similar systems
<> with varying physical constants, which show the typical trends
<> of variations for the effects of strong electron-phonon
<> interactions on different physical properties of an interface
<> polaron.
<> KP: STRONG-COUPLED POLARONS, SELF-TRAPPING ENERGY, GROUND-STATE
<> ENERGY, CYCLOTRON MASS
<>
<> (167) TI: INFLUENCE OF DIFFERENT PHONON MODES ON THE EXCITON GROUND-STATE
<> ENERGY IN A QUANTUM-WELL IN AN ELECTRIC-FIELD
<> AU: XIE_HJ, CHEN_CY, LIANG_SD
<> NA: GUANGZHOU TEACHERS COLL,DEPT PHYS,CANTON 510400,PEOPLES R CHINA
<> CHINA CTR ADV SCI & TECHNOL,WORLD LAB,CTR THEORET PHYS,BEIJING
<> 100080,PEOPLES R CHINA
<> JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1995, Vol.52, No.3,
<> pp.1776-1785
<> IS: 0163-1829
<> AB: The ground-state energy and the binding energy of an exciton in
<> a GaAs/Ga1-xAlxAs quantum well under an electric held have been
<> studied, and the interactions between excitons and different
<> phonon modes have been taken into consideration. Numerical
<> calculations show that an electric field brings more obvious
<> interface phonon effects and makes the influence of other
<> phonon modes different compared to those without an electric
<> field.
<> KP: OPTICAL-PHONON, WANNIER EXCITONS, BINDING-ENERGIES, MAGNETIC-
<> FIELD, LUMINESCENCE
<>
<> (168) TI: INTERFACE PHONONS IN SPHERICAL GAAS/AL-X GA1-XAS QUANTUM DOTS
<> AU: DELACRUZ_RM, TEITSWORTH_SW, STROSCIO_MA
<> NA: UNIV CARLOS III MADRID,DEPT INGN,E-28911 LEGANES,SPAIN
<> DUKE UNIV,DEPT PHYS,DURHAM,NC,27708
<> USA,RES OFF,RES TRIANGLE PK,NC,27709
<> JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1995, Vol.52, No.3,
<> pp.1489-1492
<> IS: 0163-1829
<> DT: Note
<> AB: Within the framework of the dielectric continuum model, the
<> interface phonon frequencies for spherical GaAs/AlxGa1-xAs
<> quantum dots are obtained as functions of the alloy composition
<> in the range x=0.2-1.0. By imposing electrostatic boundary
<> conditions, the two interface phonon frequencies are calculated
<> for the first three modes. The frequency behavior of the
<> different modes is foundto be similar. However, for each mode
<> one of the phonon frequencies is found to be strongly dependent
<> on x. It is demonstrated that these phonon modes play an
<> important sole in determining resonant optical absorption of
<> quantum dots.
<> KP: RAMAN-SCATTERING, THIN-FILMS, ELECTRON, SURFACE,
<> MICROCRYSTALLINE, HETEROSTRUCTURES, CRYSTALS, SILICON, SYSTEMS,
<> MODES
<>
<> (169) TI: POLARONIC HAMILTONIAN AND POLAR OPTICAL VIBRATIONS IN
<> MULTILAYER STRUCTURES
<> AU: KLIMIN_SN, POKATILOV_EP, FOMIN_VM
<> NA: MOLDAVIAN STATE UNIV,DEPT THEORET PHYS,MATEEVICI STR
<> 60,KISHINEV 277009,MOLDOVA
<> MOLDAVIAN STATE UNIV,PHYS MULTILAYER STRUCT
<> LAB,KISHINEV,MOLDOVA
<> JN: PHYSICA STATUS SOLIDI B-BASIC RESEARCH, 1995, Vol.190, No.2,
<> pp.441-453
<> IS: 0370-1972
<> AB: A theory of polar optical vibrations in multilayer
<> semiconductor structures is developed taking into account
<> phonon dispersion. A method of diagonalization of the equations
<> of motion for inertial polarization vectors in the finite basis
<> is used, that is founded on a finite number of degrees of
<> freedom of the system. The Hamiltonian of the electron-phonon
<> interaction is deduced. The dispersion law and the spatial
<> dependence of the obtained eigenmodes are in good agreement
<> with experimental data and microscopic models. It is shown that
<> the electron scattering rate in a magnetic field depends on the
<> chosen model of polar optical vibrations.
<> KP: ELECTRON-PHONON INTERACTION, GAAS-ALAS SUPERLATTICES,
<> SEMICONDUCTOR QUANTUM-WELLS, CONFINED LO, MODES, SCATTERING,
<> SYSTEMS, HETEROSTRUCTURES, INTERFACE, POLARIZABILITY
<>
<> (170) TI: CONFINED ELECTRON-OPTICAL PHONON-SCATTERING RATES IN 2D
<> STRUCTURES CONTAINING ELECTRON AND PHONON WALLS
<> AU: POZELA_J, JUCIENE_V, POZELA_K
<> NA: ICSC,WORLD LAB,INST SEMICOND PHYS,VILNIUS,LITHUANIA
<> JN: SEMICONDUCTOR SCIENCE AND TECHNOLOGY, 1995, Vol.10, No.8,
<> pp.1076-1083
<> IS: 0268-1242
<> AB: Two-dimensional structures containing the electron wall (the
<> barrier transparent to phonons and impenetrable by electrons)
<> and (or) the phonon wall (the barrier transparent to electrons
<> and impenetrable by phonons) are proposed. The intrasubband (1-
<> ->1) and intersubband (2-->1) electron-polar optical phonon
<> scattering rates are calculated for the quantum well divided by
<> an electron wall or a phonon wall. Independent electron and
<> phonon confinement caused by the electron and phonon walls is
<> taken into account, and a radical change of the scattering rate
<> is obtained. The electron wall increases, and the phonon wall
<> decreases, the confined electron-confined optical phonon
<> scattering rate by several times.
<>
<> (171) TI: ULTRAFAST RELAXATION OF PHOTOEXCITED CARRIERS IN SEMICONDUCTOR
<> QUANTUM WIRES - A MONTE-CARLO APPROACH
<> AU: ROTA_L, ROSSI_F, LUGLI_P, MOLINARI_E
<> NA: UNIV OXFORD,DEPT PHYS,CLARENDON LAB,PARKS RD,OXFORD OX1
<> 3PU,ENGLAND
<> UNIV MARBURG,FACHBEREICH PHYS,D-35032 MARBURG,GERMANY
<> UNIV MARBURG,ZENTRUM MAT WISSENSCH,D-35032 MARBURG,GERMANY
<> UNIV ROMA TOR VERGATA,DIPARTIMENTO INGN ELETTR,I-00133
<> ROME,ITALY
<> UNIV MODENA,DIPARTIMENTO FIS,I-41100 MODENA,ITALY
<> JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1995, Vol.52, No.7,
<> pp.5183-5201
<> IS: 0163-1829
<> AB: A detailed analysis of the cooling and thermalization process
<> for photogenerated carriers in semiconductor quantum wires is
<> presented. The energy relaxation of the nonequilibrium carrier
<> distribution is investigated for the ''realistic'' case of a
<> rectangular multisubband quantum-wire structure. By means of a
<> direct ensemble Monte Carlo simulation of both the carrier and
<> the phonon dynamics, all the nonlinear phenomena relevant for
<> the relaxation process, such as carrier-carrier interaction,
<> hot-phonon effects, and degeneracy, are investigated. The
<> results of these simulated experiments show a significant
<> reduction of the carrier-relaxation process compared to the
<> bulk case, which is mainly due to the reduced efficiency of
<> carrier-carrier scattering; on the contrary, the role of hot-
<> phonon effects and degeneracy seems to be not so different from
<> that played in bulk semiconductors.
<> KP: OPTICAL-PHONON-SCATTERING, ELECTRON-ELECTRON SCATTERING,
<> THERMALIZATION, SUPERLATTICES, TRANSPORT, DYNAMICS, WELLS,
<> HETEROSTRUCTURES, SIMULATION, INVERSION
<>
<> (172) TI: POLARON IN SUPERLATTICE MODELS WITH INFINITELY DEEP QUANTUM
<> HOLES
<> LA: Russian
<> AU: GUSEINOV_NM
<> NA: AZERBAIJAN ACAD SCI,INST PHYS,BAKU 370143,AZERBAIJAN
<> JN: FIZIKA TVERDOGO TELA, 1995, Vol.37, No.1, pp.73-78
<> IS: 0367-3294
<> KP: EFFECTIVE MASS
<>
<> (173) TI: CYCLOTRON-RESONANCE OF MAGNETOPOLARON IN CYLINDRICAL QUANTUM
<> WIRES WITH ARBITRARY MAGNETIC-FIELDS
<> AU: ZHOU_HY, GU_SW
<> NA: SHANGHAI JIAO TONG UNIV,DEPT APPL PHYS,SHANGHAI 200030,PEOPLES
<> R CHINA
<> SHANGHAI JIAO TONG UNIV,INST CONDENSED MATTER PHYS,SHANGHAI
<> 200030,PEOPLES R CHINA
<> JN: COMMUNICATIONS IN THEORETICAL PHYSICS, 1995, Vol.24, No.1,
<> pp.1-6
<> IS: 0253-6102
<> AB: By solving the effective mass equation with the variational
<> method, we studied the cyclotron resonance of magnetopolaron in
<> cylindrical quantum wires with arbitrary magnetic fields. The
<> interaction of the electron with surface-optical (SO) phonons
<> is used. Having calculated the ground state energy and the
<> excited state energy of the magnetopolaron, we obtain the
<> cyclotron resonance frequency of the magnetopolaron. The effect
<> of the electron-SO phonon interaction decreases the cyclotron
<> resonance frequency. Furthermore with the increasing strength
<> of magnetic fields, the cyclotron resonance frequency of the
<> magnetopolaron for m = 1 (m = -1) increases (decreases)
<> monotonously. When the confinement energy is much less than the
<> Landau quantization energy, our results tend to the bulk case
<> correctly. the same magnetic field strength, our results show
<> that, the larger the confinement length of the quantum wire is,
<> the smaller the absolute value of the electron-SO phonon
<> interaction energy and the cyclotron resonance frequency are.
<> KP: WELL WIRES, ENERGY, INTERFACE, HETEROSTRUCTURES, DEPENDENCE,
<> ELECTRONS, SURFACE, POLARON, PHONONS, SINGLE
<>
<> (174) TI: EFFECT OF INELASTIC PROCESSES ON TUNNELING
<> AU: BONCA_J, TRUGMAN_SA
<> NA: LOS ALAMOS NATL LAB,DIV THEORY,LOS ALAMOS,NM,87545
<> LOS ALAMOS NATL LAB,CTR NONLINEAR STUDIES,LOS ALAMOS,NM,87545
<> UNIV LJUBLJANA,JOZEF STEFAN INST,LJUBLJANA 61111,SLOVENIA
<> JN: PHYSICAL REVIEW LETTERS, 1995, Vol.75, No.13, pp.2566-2569
<> IS: 0031-9007
<> AB: We study an electron that interacts with phonons or other
<> linear or nonlinear excitations as it resonantly tunnels. The
<> method we use is based on mapping a many-body problem in a
<> large variational space exactly onto a one-body problem. The
<> method is conceptually simpler than previous Green's function
<> approaches, and allows the essentially exact numerical solution
<> of much more general problems. We solve tunneling problems with
<> transverse channels, multiple sites coupled to phonons, and
<> multiple phonon degrees of freedom and excitations.
<> KP: DOUBLE-BARRIER, PHONON INTERACTION, SOLVABLE MODEL,
<> HETEROSTRUCTURES
<>
<> (175) TI: MAGNETIC-FIELD-ENHANCED RAMAN-SCATTERING BY INTERFACE PHONONS
<> IN P-TYPE MODULATION-DOPED MULTIPLE-QUANTUM WELLS
<> AU: KRAUS_J, WEIMANN_G, PANZLAFF_K
<> NA: UNIV WURZBURG,INST PHYS,HUBLAND,D-97074 WURZBURG,GERMANY
<> TECH UNIV MUNICH,WALTER SCHOTTKY INST,D-85748 GARCHING,GERMANY
<> UNIV ULM,OPTOELEKTR ABT,D-89069 ULM,GERMANY
<> JN: JOURNAL OF PHYSICS-CONDENSED MATTER, 1995, Vol.7, No.40,
<> pp.7761-7773
<> IS: 0953-8984
<> AB: We have investigated the coupling of hole intersubband
<> transitions and phonons in p-type modulation-doped GaAs-AlxGa1-
<> xAs multiple quantum wells by means of resonance Raman
<> spectroscopy. Magnetic fields with flux densities up to B = 14
<> T were applied, oriented parallel to the growth direction. For
<> B = 0 T the spectra can be interpreted in terms of a Fano
<> interference of the zone-centre quantum well LO phonon with a
<> quasi-continuum of hole transitions between the lowest and the
<> second excited heavy-hole subband. For B <> 4 T we observe the
<> coupling of a hole intersubband transition with interface
<> phonons. The character of the latter modes is deduced from a
<> comparison of the excitation energies with values calculated
<> within a dielectric continuum model as well as from their
<> behaviour under photoexcitation. Our measurements indicate an
<> interaction of the Frohlich type, where the strength of the
<> coupling seems to increase with the in-plane wavevector of the
<> excitations. The ionized impurities in the barriers dominate
<> the relaxation of wavevector conservation in the scattering
<> process.
<> KP: OPTICAL PHONONS, INTERSUBBAND TRANSITIONS, FROHLICH INTERACTION,
<> VIBRATIONAL-MODES, GAAS, SUPERLATTICES, MAGNETOPOLARONS,
<> HETEROJUNCTIONS, INTERFERENCE, EXCITATIONS
<>
<> (176) TI: ELECTRON-PHONON SCATTERING IN ASYMMETRIC SEMICONDUCTOR QUANTUM-
<> WELL STRUCTURES
<> AU: SHI_JJ, LIU_ZX, PAN_SH
<> NA: HENAN NORMAL UNIV,DEPT PHYS,XINXIANG 453002,PEOPLES R CHINA
<> CHINESE ACAD SCI,INST PHYS,BEIJING 100080,PEOPLES R CHINA
<> CCAST,WORLD LAB,BEIJING 100080,PEOPLES R CHINA
<> JN: SUPERLATTICES AND MICROSTRUCTURES, 1995, Vol.17, No.3, pp.329-
<> 334
<> IS: 0749-6036
<> AB: We calculate scattering rates of intrasubband and intersubband
<> electronic transitions in asymmetric single quantum wells
<> (QW's) and step QW's due to interface phonons, confined bulk-
<> like LO phonons, and half-space LO phonons. The relative
<> importance of the different phonon modes is analyzed. The
<> results show that the electron-phonon scattering rates have
<> intimate relation to the QW parameters. (C) 1995 Academic Press
<> Limited
<>
<> (177) TI: INTERFACE PHONONS IN GAAS/ALAS QUANTUM DOTS
<> AU: DELACRUZ_RM
<> NA: UNIV CARLOS III,DEPT FIS,E-28911 LEGANES,SPAIN
<> JN: SUPERLATTICES AND MICROSTRUCTURES, 1995, Vol.17, No.3, pp.307-
<> 314
<> IS: 0749-6036
<> AB: Electron scattering by interface phonon modes in GaAs/AlAs
<> quantum dots is investigated. The emission rates are calculated
<> using an electron-phonon interaction Hamiltonian derived in the
<> framework of the dielectric continuum model. The effect of the
<> embedding material AlAs on the electron relaxation by interface
<> phonons is analyzed by comparing the emission rates with those
<> obtained for GaAs free standing quantum dots in vacuum. This
<> effect reduces the emission rates yielding relaxation times
<> slower than the radiative recombination lifetime of electrons
<> and holes in their ground levels. In GaAs/AlAs quantum dots, it
<> appears that the contribution of the electron relaxation via
<> interface phonon emission to the radiative decay processes is
<> less significant than the relaxation mechanisms via
<> longitudinal optical and longitudinal acoustic phonon. Faster
<> relaxation times are obtained if the interface phonon mode
<> involved in the scattering processes is antisymmetric. (C) 1995
<> Academic Press Limited
<> KP: THIN-FILMS, SCATTERING, MODES, RELAXATION, SYSTEMS, SURFACE,
<> WIRE
<>
<> (178) TI: NONPARABOLICITY EFFECTS ON TRANSITION RATES DUE TO CONFINED
<> PHONONS IN GAAS-ALGAAS QUANTUM-WELLS
<> AU: ALCALDE_AM, WEBER_G
<> NA: UNIV ESTADUAL CAMPINAS,INST FIS,CAIXA POSTAL 6165,BR-13083970
<> CAMPINAS,SP,BRAZIL
<> JN: SOLID STATE COMMUNICATIONS, 1995, Vol.96, No.10, pp.763-766
<> IS: 0038-1098
<> AB: We calculate electron-LO-confined-phonon scattering rates in
<> GaAs-AlGaAs quantum wells considering the influence of
<> nonparabolicity on the energy subbands. We find that the
<> subband nonparabolicity increases the scattering rates
<> significantly for all transitions and that this effect is more
<> pronounced as transitions from higher subbands are involved.
<> KP: SCATTERING RATES, ELECTRIC-FIELD, MODEL, SEMICONDUCTORS,
<> SUPERLATTICES, SINGLE, SLAB
<> WA: QUANTUM WELLS, SEMICONDUCTORS, ELECTRON-PHONON INTERACTIONS,
<> ELECTRONIC BAND STRUCTURE
<>
<> (179) TI: ELECTRON-PHONON INTERACTION AND TUNNELING ESCAPE PROCESS IN
<> GAAS/ALAS QUANTUM-WELLS
<> AU: HERNANDEZCABRERA_A, ACEITUNO_P, CRUZ_H
<> NA: UNIV LA LAGUNA,DEPT FIS FUNDAMENTAL & EXPTL,E-38204 LA
<> LAGUNA,SPAIN
<> JN: JOURNAL OF APPLIED PHYSICS, 1995, Vol.78, No.10, pp.6147-6150
<> IS: 0021-8979
<> AB: In this work, we have numerically integrated in space and time
<> the effective mass Schrodinger equation for an electron in a
<> GaAs/AlAs quantum well. Considering the electron-phonon
<> interaction and an external electric held, we have studied the
<> electronic tunneling escape process from semiconductor quantum
<> wells. In this way, electronic lifetimes have been obtained at
<> different well widths and applied electric fields. (C) 1995
<> American Institute of Physics.
<> KP: FIELD, MODES, SUPERLATTICES
<>
<> (180) TI: SPECTRUM OF CHARGED-PARTICLES IN THIN SEMICONDUCTING-FILMS
<> CONTACTING WITH MASSIVE CRYSTALS OF RANDOM PENETRABILITY
<> LA: Russian
<> AU: BOICHUK_VI, VOITSEKHIVSKAYA_ON, GOLOVATSKII_VA, TKACH_NV
<> NA: CHERNOVTSY STATE UNIV,CHERNOVTSY,UKRAINE
<> JN: FIZIKA TVERDOGO TELA, 1995, Vol.37, No.3, pp.861-871
<> IS: 0367-3294
<> KP: SURFACE PHONON-POLARITONS, BILAYER SYSTEMS
<>
<> (181) TI: STUDY OF INTERFACE POLARON STATES OF SIMPLE HETEROSTRUCTURES OF
<> SEMICONDUCTORS
<> LA: Russian
<> AU: BOICHUK_VI, BILYNSKII_IV
<> NA: I FRANKO STATE TEACHERS INST,DROGOBYCH,UKRAINE
<> JN: FIZIKA TVERDOGO TELA, 1995, Vol.37, No.3, pp.734-744
<> IS: 0367-3294
<> KP: PHONON
<>
<> (182) TI: CARRIER ENERGY RELAXATION-TIME IN QUANTUM-WELL LASERS
<> AU: TSAI_CY, TSAI_CY, LO_YH, EASTMAN_LF
<> NA: DE MONTFORT UNIV,SCH ENGN & MANUFACTURE,EMERGING TECHNOL RES
<> CTR,LEICESTER LE1 9BH,LEICS,ENGLAND
<> CORNELL UNIV,SCH ELECT ENGN,ITHACA,NY,14853
<> UNIV STUTTGART,INST PHYS,D-70550 STUTTGART,GERMANY
<> JN: IEEE JOURNAL OF QUANTUM ELECTRONICS, 1995, Vol.31, No.12,
<> pp.2148-2158
<> IS: 0018-9197
<> AB: Carrier energy relaxation via carrier-polar optical phonon
<> interactions with hot phonon effects in multisubband quantum-
<> well structures is theoretically studied by using both bulk
<> longitudinal optical phonons and confined longitudinal optical
<> phonons. We find that the width and the depth of quantum wells
<> only have moderate effects on carrier energy relaxation rates,
<> Our results also indicate that the difference of energy
<> relaxation rates between the quantum well and the bulk material
<> is not significant, We investigate the effects of longitudinal
<> optical phonon lifetimes on the carrier energy relaxation rate,
<> Neglect of the finite decay time of longitudinal optical
<> phonons mill significantly underestimate the carrier energy
<> relaxation time; this not only contradicts the experimental
<> results but also severely underestimates the nonlinear gain
<> coefficient due to carrier heating, The implications of our
<> theoretical results in designing high-speed quantum-well lasers
<> are discussed.
<> KP: ELECTRON-PHONON INTERACTION, NONEQUILIBRIUM LO PHONONS, POLAR
<> SEMICONDUCTORS, NONLINEAR GAIN, HOT CARRIERS, SUPERLATTICES,
<> SCATTERING, HETEROSTRUCTURES, SINGLE, MODES
<>
<> (183) TI: REDUCTION OF ELECTRON-OPTICAL PHONON-SCATTERING RATES IN A
<> QUANTUM-WELL WITH A PHONON WALL
<> AU: POZELA_J, JUCIENE_V, POZELA_K
<> NA: LITHUANIA ACAD SCI,INST SEMICOND PHYS,ICSC,WORLD LAB,LITHUANIAN
<> BRANCH,GOSTAUTO 11,VILNIUS 232600,LITHUANIA
<> JN: SEMICONDUCTOR SCIENCE AND TECHNOLOGY, 1995, Vol.10, No.12,
<> pp.1555-1560
<> IS: 0268-1242
<> AB: The intrasubband electron-polar optical phonon scattering rates
<> for interface and confined phonons are calculated. The
<> AlAs/GaAs/AlAs double heterostructures with independent
<> confinement of electrons and phonons as well as structures
<> containing a phonon wall (a phonon-reflecting barrier
<> transparent to electrons) embedded in an electron quantum well
<> (QW) are considered. It is shown that, because of the
<> independent electron and phonon confinement in the double
<> heterostructure, the scattering rate is lower than that
<> obtained in the case of electron confinement alone. The total
<> scattering rate by confined and interface phonons in the QW
<> with a phonon wall is reduced significantly as compared with
<> the rate of confined electron scattering by bulk phonons. Thus,
<> the phonon wall within the electron QW is a powerful means of
<> reducing electron scattering and enhancing, correspondingly,
<> the electron mobility in two-dimensional (2D) heterostructures.
<>
<> (184) TI: THE INTERACTION OF ELECTRONS WITH OPTICAL PHONONS IN EMBEDDED
<> CIRCULAR AND ELLIPTIC GAAS QUANTUM WIRES
<> AU: BENNETT_CR, CONSTANTINOU_NC, BABIKER_M, RIDLEY_BK
<> NA: UNIV ESSEX,DEPT PHYS,COLCHESTER CO4 3SQ,ESSEX,ENGLAND
<> JN: JOURNAL OF PHYSICS-CONDENSED MATTER, 1995, Vol.7, No.50,
<> pp.9819-9831
<> IS: 0953-8984
<> AB: We consider electronic intrasubband transitions involving the
<> confined and interface optical phonons of circular and
<> elliptical GaAs quantum wires. Detailed treatments are given
<> for a GaAs wire embedded in AIAs where the electrons are
<> confined via an infinite potential barrier. The optical phonons
<> are described using the dielectric continuum (DC) model, which
<> for the GaAs/AIAs system compares favourably with more
<> sophisticated macroscopic models and ab initio microscopic
<> calculations in its prediction for the total scattering rates.
<> The DC model has been applied previously to the circular case,
<> but here we evaluate the rates analytically. It is shown that
<> the behaviour of the electrons and phonons in elliptical wires
<> is both quantitatively and qualitatively different from that in
<> circular wires, especially as regards angular properties.
<> KP: INTERFACE PHONONS, SCATTERING RATES, LO PHONONS, WELLS,
<> HETEROSTRUCTURES, SYSTEMS, ALAS
<>
<> (185) TI: BINDING-ENERGIES OF EXCITONS IN IONIC QUANTUM-WELL STRUCTURES
<> AU: ANTONELLI_A, CEN_J, BAJAJ_KK
<> NA: UNIV ESTADUAL CAMPINAS,UNICAMP,INST FIS GLEB WATAGHIN,CAIXA
<> POSTAL 6165,BR-13081 CAMPINAS,SP,BRAZIL
<> EMORY UNIV,DEPT PHYS,ATLANTA,GA,30322
<> JN: SEMICONDUCTOR SCIENCE AND TECHNOLOGY, 1996, Vol.11, No.1,
<> pp.74-79
<> IS: 0268-1242
<> AB: We have calculated the binding energies of excitons in quantum
<> well structures based on ionic semiconductors by including the
<> electron-hole interactions with the longitudinal optical phonon
<> field. We have taken into account these interactions by using
<> different effective interaction potentials between the electron
<> and the hole as derived by Haken, by Aldrich and Bajaj, and by
<> Pollman and Buttner. We have calculated the binding energies of
<> excitons in several ionic quantum well structures as functions
<> of well width using these effective potentials by following a
<> variational approach, We find that the values of the exciton
<> binding energies calculated using these potentials are always
<> larger than those obtained using a Coulomb potential screened
<> by a static dielectric constant. We compare our results with
<> those of some recent calculations.
<> KP: OPTICAL-PHONON, DIODES, SEMICONDUCTORS, SYSTEM
<>
<> (186) TI: ELASTIC VIBRATIONS OF MICROTUBULES IN A FLUID
<> AU: SIRENKO_YM, STROSCIO_MA, KIM_KW
<> NA: N CAROLINA STATE UNIV,DEPT ELECT & COMP ENGN,RALEIGH,NC,27695
<> USA,RES OFF,RES TRIANGLE PK,NC,27709
<> JN: PHYSICAL REVIEW E, 1996, Vol.53, No.1 PtB, pp.1003-1010
<> IS: 1063-651X
<> AB: We study theoretically vibrational properties of microtubules
<> (MTs), which are long hollow cylindrical macromolecules with a
<> diam. of the order of 25 nm and serve as a major component of
<> cytoskeleton in eukariotic cells. Modeling MTs by thin elastic
<> cylindrical shells, we derive the eigenfrequencies and
<> eigenmodes of confined elastic vibrations in a shell-fluid
<> system. Numerical calculations, based on recently obtained
<> experimental data for Young's modulus of MT, show that MT-water
<> system supports interface elastic waves with maximal
<> frequencies in a gigahertz range. In a long-wavelength limit,
<> there exist three axisymmetric acoustic waves with velocities
<> of about 200 to 600 m/s, and an infinite set of helical waves
<> with a parabolic dispersion law.
<> KP: F-ACTIN, DYNAMIC INSTABILITY, CYLINDRICAL-SHELLS, FLEXURAL
<> RIGIDITY, TRYPSIN-INHIBITOR, PHONON, SCATTERING, MODES,
<> SIMULATION, PROTEINS
<>
<> (187) TI: POTENTIALS INDUCED BY THE ELECTRON-OPTICAL-PHONON INTERACTION
<> IN A QUANTUM-WELL
<> AU: ZHAO_GZ, PAN_SH
<> NA: ACAD SINICA,INST PHYS,POB 603,BEIJING 100080,PEOPLES R CHINA
<> CHINA CTR ADV SCI & TECHNOL,WORLD LAB,BEIJING 100080,PEOPLES R
<> CHINA
<> JN: ZEITSCHRIFT FUR PHYSIK B-CONDENSED MATTER, 1996, Vol.99, No.3,
<> pp.375-380
<> IS: 0722-3277
<> AB: The potential induced by the electron-optical-phonon
<> interaction in a quantum well (QW) is investigated by means of
<> the perturbation theory. We consider the interactions of an
<> electron with both bulklike confined longitudinal optical (LO)
<> phonons and four branches of interface optical (IO) phonons.
<> The spatial distribution V-i(z) of the induced potential for QW
<> structures with different heterolayer compositions and
<> different well widths is calculated in detail. The numerical
<> results show that the heterolayer composition of the QW plays
<> an important role in determining the shape of V-i(z) and that
<> the existence of IO-phonons is important to the electronic
<> states in QWs.
<> KP: POLAR CRYSTALS, DOUBLE HETEROSTRUCTURES, DIELECTRIC SLAB,
<> EFFECTIVE MASS, INTERFACE, MODES, ENERGY, HETEROJUNCTIONS,
<> POLARIZABILITY, SUPERLATTICES
<>
<> (188) TI: HEAVY-HOLE SCATTERING BY CONFINED NONPOLAR OPTICAL PHONONS IN A
<> SINGLE SI1-XGEX/SI QUANTUM-WELL
<> AU: SUN_G, FRIEDMAN_L
<> NA: UNIV MASSACHUSETTS,ENGN PROGRAM,BOSTON,MA,02125
<> ROME LAB,EROC,BEDFORD,MA,01731
<> JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1996, Vol.53, No.7,
<> pp.3966-3974
<> IS: 0163-1829
<> AB: Intrasubband and intersubband scattering rates of heavy holes
<> are obtained due to confined nonpolar optical phonons in a Si1-
<> xGex quantum well with Si barriers. Guided and interface Ge-Si
<> and Ge-Ge modes and unconfined Si-Si modes are considered. A
<> continuum model is used for the two components of the ionic
<> displacement of confined vibrations: the uncoupled s-polarized
<> TO mode and the hybrid of the LO and p-polarized TO modes. The
<> guided mode is obtained using the model of a quantum well with
<> infinitely rigid barriers and the interface mode is derived
<> from the hydrodynamic boundary conditions. While the total
<> intersubband scattering rates are reduced as a result of
<> confinement, the opposite is found for the intrasubband
<> scattering. Depending on the well width and Ge content, the
<> intersubband scattering rates are reduced by a factor of 2-4
<> with respect to their values for no confinement. Thus one would
<> expect comparable enhancement in the intersubband lifetimes
<> crucial to the population inversion in a Si1-xGex/Si
<> intersubband laser.
<> KP: GAAS-ALAS SUPERLATTICES, SEMICONDUCTOR HETEROSTRUCTURES,
<> ELECTRON, MODES
<>
<> (189) TI: RESONANT RAMAN-SCATTERING IN GAAS/ALAS SUPERLATTICES - THE ROLE
<> OF ELECTRON STATE MIXING
<> AU: MLAYAH_A, CARLES_R, SAYARI_A, CHTOUROU_R, CHARFI_FF, PLANEL_R
<> NA: UNIV TOULOUSE 3,PHYS SOLIDES LAB,118 ROUTE NARBONNE,F-31062
<> TOULOUSE,FRANCE
<> FAC SCI TUNIS,LAB SPECT MOL,TUNIS 1060,TUNISIA
<> CTR NATL ETUD TELECOMMUN,CNRS,MICROSTRUCT & MICROELECTR LAB,F-
<> 92225 BAGNEUX,FRANCE
<> JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1996, Vol.53, No.7,
<> pp.3960-3965
<> IS: 0163-1829
<> AB: In this work, resonant Raman measurements on a short-period
<> GaAs/AlAs superlattice are presented. Under resonant
<> excitation, near the direct band gap, zone-edge acoustic
<> phonons are observed. Similar scattering has been also recorded
<> in the resonant Raman spectra of AlxGa1-xAs alloy layer. We
<> show that intervalley electron scattering is at the origin of
<> the observed similarities. This scattering is attributed to the
<> superlattice potential for the GaAs/AlAs superlattice, and to
<> the potential fluctuations for the AlxGa1-xAs alloy. The
<> present analysis gives a clear interpretation of the Raman
<> scattering by zone-edge acoustic phonons in both systems.
<> Moreover, the role of disorder is discussed in terms of an
<> activation of folded acoustic and coupled confined-interface
<> phonons.
<> KP: GAAS-ALAS SUPERLATTICES, INTERFACE PHONONS, OPTICAL PHONONS,
<> QUANTUM-WELLS, CONFINED LO, ALXGA1-XAS, ALLOYS, MODES
<>
<> (190) TI: BINDING-ENERGIES OF EXCITONS IN IONIC QUANTUM-WELL STRUCTURES
<> AU: ANTONELLI_A, CEN_J, BAJAJ_KK
<> NA: EMORY UNIV,DEPT PHYS,ATLANTA,GA,30322
<> JN: NUOVO CIMENTO DELLA SOCIETA ITALIANA DI FISICA D-CONDENSED
<> MATTER ATOMIC MOLECULAR AND CHEMICAL PHYSICS FLUIDS PLASMAS
<> BIOPHYSICS, 1995, Vol.17, No.11-12, pp.1343-1347
<> IS: 0392-6737
<> AB: We have calculated the binding energies of excitons in quantum
<> well structures based on ionic semiconductors by including the
<> electron-hole interactions with the longitudinal-optical-phonon
<> field. We have taken into account these interactions by using
<> different effective interaction potentials between the electron
<> and the hole as derived by Haken, Aldrich and Bajaj, and
<> Pollman and Buttner. We have calculated the binding energies of
<> excitons in several ionic quantum well structures as functions
<> of well width using these effective potentials following a
<> variational approach. We find that the values of the exciton
<> binding energies calculated using these potentials are always
<> larger than those obtained using a Coloumb potential screened
<> by static dielectric constant.
<> KP: OPTICAL-PHONON, SEMICONDUCTORS, SYSTEM
<>
<> (191) TI: HOPPING CONDUCTION IN SEMICONDUCTOR SUPERLATTICES IN A
<> QUANTIZED MAGNETIC-FIELD
<> AU: SHON_NH, NAZARENO_HN
<> NA: UNIV BRASILIA,INT CTR CONDENSED MATTER PHYS,BR-70919900
<> BRASILIA,DF,BRAZIL
<> JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1996, Vol.53, No.12,
<> pp.7937-7944
<> IS: 0163-1829
<> AB: Hopping conduction between localized Stark states in
<> superlattices in longitudinal electric and magnetic fields is
<> investigated. Electron scattering with acoustic phonons, short-
<> range impurities, and with polar-optic phonons are taken into
<> consideration. The expression for hopping current formally
<> exhibits a series of maxima at the points p omega(c) = n theta
<> [Stark-cyclotron resonance (SCR)] or at p omega(c) = \n
<> theta+/-omega(ol)\ [stark-cyclotron-phonon resonance (SCPR)]
<> (omega(c) and theta are cyclotron and Bloch frequencies,
<> respectively, omega(ol) are optic-phonon frequency modes in
<> superlattices, and p and n are integer numbers). However, the
<> SCR's are strongly suppressed due to finite collisional
<> broadening and are not easily detected experimentally. Within
<> the framework of the dielectric continuum model, numerical
<> calculations show that the amplitude of SCPR is much weaker
<> than the amplitude of SCR and it does not give contributions to
<> the hopping current. These observations are in good qualitative
<> agreement with recent experiments.
<> KP: ENVELOPE-FUNCTION APPROXIMATION, ELECTRON-PHONON INTERACTION,
<> NEGATIVE DIFFERENTIAL CONDUCTIVITY, LATTICE BAND-STRUCTURE,
<> EXCITON STARK LADDER, GAAS/ALAS SUPERLATTICES, INDUCED
<> LOCALIZATION, MINIBAND
<>
<> (192) TI: ACOUSTIC-PHONON QUANTIZATION IN BURIED WAVE-GUIDES AND
<> RESONATORS
<> AU: STROSCIO_MA, SIRENKO_YM, YU_S, KIM_KW
<> NA: USA,RES OFF,POB 12211,RES TRIANGLE PK,NC,27709
<> N CAROLINA STATE UNIV,DEPT ELECT & COMP ENGN,RALEIGH,NC,27695
<> JN: JOURNAL OF PHYSICS-CONDENSED MATTER, 1996, Vol.8, No.13,
<> pp.2143-2151
<> IS: 0953-8984
<> AB: Starting from a classical Hamiltonian for nonhomogeneous
<> elastic media, a procedure is developed for acoustic phonon
<> quantization in resonators as well as linear and planar
<> waveguides. The formalism is illustrated in an example of
<> acoustic phonon modes in a buried cylindrical waveguide. The
<> deformation potential Hamiltonian for electron-acoustic phonon
<> interaction is also obtained.
<> KP: SEMICONDUCTOR SUPERLATTICES, ELECTRON-GAS, MODES, TRANSMISSION,
<> HETEROSTRUCTURES, LOCALIZATION, CARRIERS, WIRES
<>
<> (193) TI: EXCITONIC POLARONS IN QUASI-2-DIMENSIONAL STRUCTURES
<> AU: THILAGAM_A, SINGH_J
<> NA: NO TERR UNIV,FAC SCI,DARWIN,NT 0909,AUSTRALIA
<> JN: APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING, 1996, Vol.62,
<> No.5, pp.445-450
<> IS: 0721-7250
<> AB: A theory of excitonic polarons in semiconductor quantum wells
<> is presented. Using a unitary transformation, we have
<> diagonalized the exciton-phonon interaction operator in a
<> quasi-two-dimensional system partially and then calculated the
<> ground-state energy of an excitonic polaron. We have
<> numerically evaluated the energy gap shift and effective mass
<> of an excitonic polaron. We have numerically evaluated the
<> energy gap shift and effective mass of an excitonic polaron in
<> GaAs-AlxGa1-xAs systems. The results obtained here indicate
<> that the polaronic effect is significant in the case of the
<> light hole excitons in quantum wells of small well widths.
<> KP: SEMICONDUCTOR QUANTUM-WELLS, BINDING-ENERGIES, PHONON
<> INTERACTION, GAAS, HETEROSTRUCTURES, STATES
<>
<> (194) TI: PRESURFACE EXCITON SPECTRUM AT FINITE TEMPERATURES
<> AU: TKACH_MV, PAZIUK_VV
<> NA: STATE UNIV CHERNIVTSI,DEPT THEORET PHYS,KOTSYUBINSKOGO
<> 2,CHERNOVTSY 274012,UKRAINE
<> JN: PHYSICA STATUS SOLIDI B-BASIC RESEARCH, 1996, Vol.194, No.2,
<> pp.525-539
<> IS: 0370-1972
<> AB: The Hamiltonian of the presurface excitons interacting with the
<> bulk and interface phonons in a heterosystem with a plane
<> interface is obtained in the representation of second
<> quantization in all variables. The spectrum parameters (shift
<> and half-width) of the shape function of the basic band at
<> arbitrary temperatures are calculated with the help of the
<> Green Function method. The temperature dependence of the
<> spectrum parameters is studied and the physical mechanism of
<> their formation is established on the example of particular
<> heterosystems.
<> KP: ELECTRON PHONON INTERACTION, SEMICONDUCTOR QUANTUM-WELLS,
<> DOUBLE HETEROSTRUCTURES, BILAYER SYSTEMS, ENERGY
<>
<> (195) TI: SCREENING EFFECTS ON THE CONFINED AND INTERFACE POLARONS IN
<> CYLINDRICAL QUANTUM WIRES
<> AU: TANATAR_B, GUVEN_K, BENNETT_CR, CONSTANTINOU_NC
<> NA: BILKENT UNIV,DEPT PHYS,BILKENT 06533,TURKEY
<> UNIV ESSEX,DEPT PHYS,COLCHESTER CO4 3SQ,ESSEX,ENGLAND
<> JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1996, Vol.53, No.16,
<> pp.10866-10870
<> IS: 0163-1829
<> AB: We study the contribution of confined and interface phonons to
<> the polaron energy in quantum-well wires. We use a
<> dispersionless, macroscopic continuum model to describe the
<> phonon confinement in quantum wires of circular cross section.
<> Surface phonon modes of a free-standing wire and interface
<> phonon modes of a wire embedded in a dielectric material are
<> also considered. Polaron energy is calculated by variationally
<> incorporating the dynamic screening effects. We find that the
<> confined and interface phonon contribution to the polaron
<> energy is comparable to that of bulk phonons in the density
<> range N = 10(5)-10(7) cm(-1). Screening effects within the
<> random-phase approximation significantly reduce the electron-
<> confined phonon interaction, whereas the exchange-correlation
<> contribution tends to oppose this trend at lower densities.
<> KP: ELECTRON-PHONON INTERACTION, LO PHONONS, SELF-ENERGY, WELL-
<> WIRES, GAAS, HETEROSTRUCTURES, GAS, MAGNETOPOLARON, STATES,
<> MODES
<>
<> (196) TI: HOT LUMINESCENCE AND ELECTRON-PHONON INTERACTION IN STRUCTURES
<> WITH QUANTUM-WELLS
<> AU: MIRLIN_DN, ZAKHARCHENYA_BP, RESHINA_II, RODINA_AV, SAPEGA_VF,
<> SIRENKO_AA, USTINOV_VM, ZHUKOV_AE, EGOROV_AY
<> NA: AF IOFFE PHYS TECH INST,POLITEKHNICHESKAYA 26,ST PETERSBURG
<> 194021,RUSSIA
<> JN: SEMICONDUCTORS, 1996, Vol.30, No.4, pp.377-380
<> IS: 1063-7826
<> AB: The electron-phonon interaction in structures with GaAs/AlAs
<> and GaAs/AlxGa1-xAs quantum wells was investigated
<> experimentally by the hot-photoluminescence method. The rate of
<> intraband scattering of 200-meV hot electrons by phonons was
<> measured as a function of the quantum-well widths in the range
<> 40-140 Angstrom. The energy and the type of phonons that make
<> the main contribution to the energy relaxation process is
<> determined directly from the energy losses in the hot-
<> luminescence spectrum. The results are compared for structures
<> with different barrier compositions. The rates of electron
<> scattering by different types of phonons are calculated on the
<> basis of a continuum dielectric model. The experimental results
<> agree satisfactorily with these calculations. (C) 1996 American
<> Institute of Physics.
<> KP: SUPERLATTICES, SCATTERING
<>
<> (197) TI: CARRIER PLASMON-POLAR PHONON COUPLING AT SEMICONDUCTOR SURFACES
<> AU: INAOKA_T
<> NA: IWATE UNIV,FAC ENGN,DEPT MAT SCI & TECHNOL,4-3-5
<> UEDA,MORIOKA,IWATE 020,JAPAN
<> JN: SCIENCE REPORTS OF THE RESEARCH INSTITUTES TOHOKU UNIVERSITY
<> SERIES A-PHYSICS CHEMISTRY AND METALLURGY, 1996, Vol.41, No.2,
<> pp.119-131
<> IS: 0040-8808
<> AB: We investigate the carrier plasmon-polar phonon coupling at
<> semiconductor surfaces by taking account of the dielectric
<> response of a semi-infinite carrier-electron gas and the polar-
<> phonon polarization. The dynamical response of carriers is
<> treated with the random-phase approximation, and the phonon
<> polarization is described by the Lorentzian oscillator model.
<> The coupling character of each coupled surface mode can be
<> clarified by decomposing the induced charge-density
<> distribution into a carrier component due to carrier density
<> fluctuation, a phonon component originating from longitudinal
<> polar-phonon polarization, and two on-surface components
<> arising from termination of the phonon and the background
<> polarization at the surface. The spatial structure of each
<> surface mode can be visualized in the contour map showing the
<> induced charge-density distribution and in the electric-field
<> profile. We examine the coupling character and the spatial
<> structure of each coupled surface mode, the evolution of the
<> character and the structure of each mode with change of carrier
<> concentration, and the origin of three coupled surface modes.
<> KP: ENERGY-LOSS SPECTROSCOPY, SPACE-CHARGE LAYER, GAAS(110)
<> SURFACES, ACCUMULATION LAYER, EXCITATIONS, INAS(110), SPECTRA,
<> HREELS, MODE, GAAS
<> WA: CARRIER PLASMON, POLAR PHONON, SEMICONDUCTOR SURFACE, COUPLING
<> CHARACTER, SPATIAL STRUCTURE
<>
<> (198) TI: CARRIER-CONCENTRATION DEPENDENCE OF PLASMON-POLAR PHONON
<> COUPLING AT SEMICONDUCTOR SURFACES
<> AU: INAOKA_T
<> NA: IWATE UNIV,FAC ENGN,DEPT MAT SCI & TECHNOL,4-3-5
<> UEDA,MORIOKA,IWATE 020,JAPAN
<> JN: SURFACE SCIENCE, 1996, Vol.351, No.1-3, pp.259-276
<> IS: 0039-6028
<> AB: We investigate the carrier-concentration dependence of plasmon-
<> polar phonon coupling at semiconductor surfaces by taking
<> account of the dielectric response of a semi-infinite carrier-
<> electron gas and the polar-phonon polarization. The dynamical
<> response of carriers is treated with the random-phase
<> approximation, and the phonon polarization is described by the
<> Lorentzian oscillator model. The induced charge-density
<> distribution in each coupled surface mode consists of a carrier
<> component due to carrier density fluctuation, a phonon
<> component originating from longitudinal polar-phonon
<> polarization, and two on-surface components arising from
<> termination of the phonon and the background polarization at
<> the surface. The coupling character reveals itself in the
<> amplitude ratio and the phase relation among these induced-
<> charge components in variation along the propagating direction.
<> This coupling character is reflected in the way in which each
<> induced-charge component contributes to the energy loss
<> involved in the dynamical surface response. The spatial
<> structure of each coupled surface mode can be visualized in the
<> contour map showing the induced charge-density distribution and
<> in the electric-field profile. We follow the evolution of the
<> coupling character and the spatial structure of each coupled
<> surface mode with change of carrier concentration passing
<> through a strong-coupling regime.
<> KP: ENERGY-LOSS SPECTROSCOPY, SPACE-CHARGE LAYER, COLLECTIVE
<> EXCITATIONS, DIELECTRIC RESPONSE, ACCUMULATION LAYERS,
<> GAAS(110) SURFACES, INAS(110), DEPLETION, SPECTRA, HREELS
<> WA: DIELECTRIC PHENOMENA, ELECTRON DENSITY, EXCITATION SPECTRA
<> CALCULATIONS, ELECTRON ENERGY LOSS SPECTROSCOPY, GALLIUM
<> ARSENIDE, INDIUM ANTIMONIDE, MANY BODY AND QUASI-PARTICLE
<> THEORIES, PHONONS, PLASMONS
<>
<> (199) TI: RADIATION-PATTERNS OF ACOUSTIC PHONONS EMITTED BY HOT-ELECTRONS
<> IN A QUANTUM-WELL
<> AU: MITIN_VV, PAULAVICIUS_G, BANNOV_NA, STROSCIO_MA
<> NA: WAYNE STATE UNIV,DEPT ELECT & COMP ENGN,DETROIT,MI,48202
<> USA,RES OFF,RES TRIANGLE PK,NC,27709
<> JN: JOURNAL OF APPLIED PHYSICS, 1996, Vol.79, No.12, pp.8955-8963
<> IS: 0021-8979
<> AB: The acoustic phonon radiation patterns and acoustic phonon
<> spectra due to electron-acoustic-phonon interaction in a double
<> barrier quantum well have been investigated by solving both the
<> kinetic equations for electrons and phonons. The acoustic
<> phonon radiation patterns have strongly pronounced maximum in
<> the directions close to the perpendicular to the quantum well
<> direction. The radiation pattern anisotropy is explained in
<> terms of possible electron transitions, electron distribution
<> function, and the Hamiltonian of electron-phonon interaction.
<> It was shown that, the simple assumption that emitted phonons
<> always have a perpendicular wave-vector component of the order
<> of 2 pi/a, where a is the width of the quantum well, cannot
<> explain the strong anisotropy of the radiation patterns. More
<> detailed analysis is required and has been carried out. The
<> emitted acoustic phonon spectra have maxima at energies 2 pi
<> HBARu/a, where u is the sound velocity. (C) 1996 American
<> Institute of Physics.
<> KP: QUANTIZING MAGNETIC-FIELD, EMISSION, GAS
<>
<> (200) TI: INTERACTION BETWEEN AN ELECTRON AND OPTICAL PHONONS IN POLAR
<> SEMICONDUCTOR HETEROSTRUCTURES
<> AU: SHI_JJ, PAN_SH, LIU_ZX
<> NA: CHINA CTR ADV SCI & TECHNOL,WORLD LAB,POB 8730,BEIJING
<> 100080,PEOPLES R CHINA
<> HENAN NORMAL UNIV,DEPT PHYS,XINXIANG 453002,PEOPLES R CHINA
<> CHINESE ACAD SCI,INST PHYS,BEIJING 100080,PEOPLES R CHINA
<> JN: ZEITSCHRIFT FUR PHYSIK B-CONDENSED MATTER, 1996, Vol.100, No.3,
<> pp.353-364
<> IS: 0722-3277
<> AB: Interface phonons and bulk-like longitudinal-optical (LO)
<> phonons and their interaction with an electron are studied for
<> a finite four-layer heterostructure (FFLHS). An analysis of the
<> field eigenvectors shows that, in the vicinity of the
<> Brillouin-zone center, an interface transverse-optical (TO)
<> mode oscillates at the bulk LO frequency, and an interface LO
<> mode oscillates at the bulk TO frequency. Analytic expressions
<> and numerical illustrations for dispersion relations of
<> interface modes and for electron-phonon coupling functions and
<> scattering rates are obtained for finite, semi-infinite and
<> infinite quantum well (QW) structures which are important
<> special cases of an FFLHS. It is shown that the scattering
<> rates depend strongly on the well width of a QW structure, and
<> that interface modes are much more important than bulk LO modes
<> when the well width is small. The calculated results also show
<> that the usual selection rules for intersubband and
<> intrasubband transitions break down in asymmetric
<> heterostructures. Moreover, we have found an interesting
<> result. That is, in comparison with the negligibly small
<> interaction between an electron and the lowest-frequency
<> interface-mode in symmetric single QWs and commonly used step
<> QWs, this interaction may be very large in asymmetric single
<> QWs and general step QWs.
<> KP: QUANTUM-WELLS, COLLECTIVE EXCITATIONS, SCATTERING RATES,
<> DIELECTRIC SLAB, LO PHONONS, INTERFACE, MODES, SUPERLATTICES,
<> CRYSTALS, HETEROJUNCTIONS
<>
<> **** End of Data ****
<>
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<> Date: Fri, 12 Dec 1997 12:29:28 +0100
<> Message-Id: <97121212292877@alpha1.bids.ac.uk>
<> From: bids_isi@alpha1.bids.ac.uk (BIDS ISI Service)
<> To: eenpk%bloch.leeds.ac.uk@bids.ac.uk
<> Subject: BIDS-cite-mori_n(2/2)
<> X-VMS-To: eenpk@bloch.leeds.ac.uk
<> Status: O
<>
<> Copyright 1997, Institute for Scientific Information Inc.
<>
<> Database: Science Citation Index
<>
<>
<> (201) TI: EFFECT OF AN ELECTRIC-FIELD ON ELECTRON-INTERFACE-PHONON
<> SCATTERING IN A GRADED QUANTUM-WELL
<> AU: ZHU_JL, DUAN_WH, GU_BL, WU_J
<> NA: TSING HUA UNIV,DEPT PHYS,BEIJING 100084,PEOPLES R CHINA
<> CHINA CTR ADV SCI & TECHNOL,WORLD LAB,BEIJING 100080,PEOPLES R
<> CHINA
<> JN: PHYSICS LETTERS A, 1996, Vol.215, No.5-6, pp.309-316
<> IS: 0375-9601
<> AB: Within the dielectric continuum model, the effect of an applied
<> longitudinal electric field on electron-interface-phonon
<> scattering is studied for the graded quantum well of Ga1-xAlxAs
<> with a Ga0.6Al0.4As barrier, and compared with that in a
<> staircase-like square quantum well structure, The electron
<> subband and interface phonon modes are calculated using the
<> method of series expansion. The intrasubband and intersubband
<> scattering rates are obtained as functions of the applied
<> electric field, and the influence of the composition gradient
<> of a graded quantum well on the scattering rates is shown. It
<> is found that the variation of the interface-phonon scattering
<> rates with the applied electric field in a graded quantum well
<> structure is significantly different from that in a staircase-
<> like square quantum well structure. However, there is much less
<> difference in the variation of the total scattering rates
<> between the two structures.
<> KP: PHOTOCURRENT SPECTROSCOPY, FROHLICH INTERACTION, DIFFERENT
<> SHAPES, SINGLE, GAAS, POLARIZABILITY, SUPERLATTICES,
<> TRANSITIONS, GA1-XALXAS, CRYSTALS
<>
<> (202) TI: POLARON EFFECTS ON THE OPTICAL 2ND-HARMONIC GENERATION IN A
<> QUANTUM-WELL WITHIN AN ELECTRIC-FIELD
<> AU: GUO_KX, CHEN_CY
<> NA: CHINA CTR ADV SCI & TECHNOL,WORLD LAB,POB 8730,BEIJING
<> 100080,PEOPLES R CHINA
<> GUANGZHOU TEACHERS COLL,DEPT PHYS,GUANGZHOU 510400,PEOPLES R
<> CHINA
<> JN: SOLID STATE COMMUNICATIONS, 1996, Vol.99, No.5, pp.363-367
<> IS: 0038-1098
<> AB: Theoretical predictions of polaron effects on the second-
<> harmonic generation due to a resonant intersubband transition
<> in a quantum well within an electric field are presented. The
<> asymmetry of the quantum well due to the electric field
<> accounts for the nonvanishing of the second-order
<> susceptibilities. It is shown that the second-harmonic
<> generation of our model is over 10 times larger than that of
<> the model where the electron-LO-phonon interaction is ignored.
<> It is also found that the optical second-harmonic generation in
<> a quantum well with an applied electric held increases with
<> strengthening electric field, but decreases with increasing
<> well width. It is interesting that the wider the quantum well
<> becomes, the less influence the electric field has on the
<> optical second-harmonic generation. Copyright (C) 1996 Elsevier
<> Science Ltd
<> KP: GROUND-STATE ENERGY, PHONON INTERACTION, EFFECTIVE MASS, 2
<> DIMENSIONS, HETEROSTRUCTURES, SUSCEPTIBILITY, SCATTERING,
<> LUMINESCENCE, SINGLE
<> WA: OPTICAL 2ND-HARMONIC GENERATION, POLARON EFFECT
<>
<> (203) TI: OPTICAL-PHONON MODES AND ELECTRON-OPTICAL-PHONON INTERACTION IN
<> A COUPLED-QUANTUM-WELL
<> AU: SHI_JJ
<> NA: HENAN NORMAL UNIV,DEPT PHYS,XINXIANG 453002,PEOPLES R CHINA
<> CHINESE CTR ADV SCI & TECHNOL,WORLD LAB,BEIJING 100080,PEOPLES
<> R CHINA
<> JN: ACTA PHYSICA SINICA-OVERSEAS EDITION, 1996, Vol.5, No.6,
<> pp.438-449
<> IS: 1004-423X
<> AB: By applying the dielectric continuum model, optical-phonon
<> modes of the lattice vibration and a complete: interaction
<> Frohlich-like Hamiltonian between an electron and the optical
<> phonons including the interface phonons, the confined LO
<> phonons and the half-space LO phonons are derived for a general
<> coupled quantum well (GCQW) structure of polar crystals. The
<> dispersion curves of the interface modes and the electron-
<> interface-phonon coupling function as functions of coordinate z
<> and wavenumber ic are given and discussed for a GCQW. We find
<> that there are eight (not ten) frequency solutions for the
<> interface optical-phonon modes in GCQW and that, in the long-
<> wavelength limit, the longitudinal and transverse modes; in the
<> two side materials 1 and 5 are forbidden and two new frequency
<> solutions wi are obtained instead. Moreover, we also find that
<> the electron-interface-phonon coupling functions am complicated
<> functions of k and that the phonons with long wavelengths are
<> important and the higher-frequency modes are more important
<> than the lower-frequency modes for the electron-phonon
<> interaction.
<> KP: POLAR CRYSTALS, DOUBLE HETEROSTRUCTURES, DIELECTRIC SLAB,
<> INTERFACE, HETEROJUNCTIONS, POLARIZABILITY, SURFACE
<>
<> (204) TI: EFFECTIVE INTERACTION OF ELECTRONS IN A SINGLE-HETEROSTRUCTURE
<> BY EXCHANGE OF THE INTERFACE PHONONS
<> AU: ZHENG_YS, LU_TQ, ZHANG_CX, WU_XH, SU_WH
<> NA: JILIN UNIV,DEPT PHYS,GRP SOLID STATE PHYS,CHANGCHUN
<> 130023,PEOPLES R CHINA
<> JILIN UNIV,CTR THEORET PHYS,CHANGCHUN 130023,PEOPLES R CHINA
<> CCAST,WORLD LAB,BEIJING 100080,PEOPLES R CHINA
<> JN: PHYSICS LETTERS A, 1996, Vol.220, No.1-3, pp.120-124
<> IS: 0375-9601
<> AB: The electron-electron interaction potential by exchange of
<> virtual interface phonons in a single-heterostructure is
<> studied in the presence and absence of a perpendicular magnetic
<> field. It is shown that the effective potential is different
<> from that of the three-dimensional case and the magnetic field
<> plays an interesting role in changing the strength of the
<> effective potential.
<> KP: POLARON
<>
<> (205) TI: ELECTRON INTERACTION WITH CONFINED ACOUSTIC PHONONS IN
<> CYLINDRICAL QUANTUM WIRES VIA DEFORMATION POTENTIAL
<> AU: YU_S, KIM_KW, STROSCIO_MA, IAFRATE_GJ, BALLATO_A
<> NA: N CAROLINA STATE UNIV,DEPT ELECT & COMP ENGN,RALEIGH,NC,27695
<> USA,RES OFF,RES TRIANGLE PK,NC,27709
<> USA,RES LAB,PHYS SCI DIRECTORATE,FT MONMOUTH,NJ,07703
<> N CAROLINA STATE UNIV,DEPT PHYS,RALEIGH,NC,27695
<> JN: JOURNAL OF APPLIED PHYSICS, 1996, Vol.80, No.5, pp.2815-2822
<> IS: 0021-8979
<> AB: The effects of phonon confinement on electron-acoustic-phonon
<> scattering is studied in cylindrical semiconductor quantum
<> wires. In the macroscopic elastic continuum model, the
<> confined-phonon dispersion relations are obtained for several
<> crystallographic directions with the two cardinal boundary
<> conditions: free-surface and clamped-surface boundary
<> conditions. The scattering rates due to the deformation
<> potential interaction are obtained for these confined phonons
<> and are compared with those of bulk-like phonons for a number
<> of quantum wire materials. The results show that the inclusion
<> of acoustic phonon confinement effects may be crucial for
<> calculating accurate low-energy electron scattering rates in
<> nanostructures. It is also demonstrated that the scattering
<> rates may be significantly influenced by the direction of
<> phonon propagation, especially for low-energy electrons.
<> Furthermore, it has been found that there is a scaling rule
<> governing the directional dependence of the scattering rates:
<> the directions characterized by small Poisson ratios exhibit
<> large scattering rates. (C) 1996 American Institute of Physics.
<> KP: BRILLOUIN-SCATTERING, RAMAN-SCATTERING, FILMS, SUPERLATTICES,
<> SYSTEMS, MODES, RATES
<>
<> (206) TI: CALCULATIONS OF MICROWAVE AND MILLIMETER-WAVE RESPONSE
<> CHARACTERISTICS OF THE 2-DIMENSIONAL HOT-ELECTRON GAS IN
<> IN0.53GA0.47AS QUANTUM-WELLS
<> AU: GHOSH_PK, SARKAR_SK, CHATTOPADHYAY_D
<> NA: INST RADIOPHYS & ELECT,92 ACHARYA PRAFULLA CHANDRA RD,CALCUTTA
<> 700009,W BENGAL,INDIA
<> BENGAL ENGN COLL,DEPT ELECT & TELECOMMUN,HOWRAH 711103,INDIA
<> JN: PHYSICA STATUS SOLIDI A-APPLIED RESEARCH, 1996, Vol.156, No.2,
<> pp.365-374
<> IS: 0031-8965
<> AB: The small-signal mobility of the two-dimensional degenerate hot
<> electrons in a square quantum well of In0.53Ga0.47As is
<> calculated in the microwave and millimeterwave regime. The
<> carrier energy loss via polar optic phonons and momentum losses
<> through deformation potential acoustic, background ionized
<> impurity, and alloy disorder scatterings are considered. The ac
<> mobility is found constant up to about 100 GHz while the
<> alternating current lags behind the applied field above about
<> 10 GHz. The ac mobility and the phase lag increase with the
<> rise of both she channel width and the 2D carrier
<> concentration. The 3dB cutoff frequency decreases with
<> increasing width of tile channel and is larger for higher bias
<> fields. The cutoff frequency is higher for 300 than for 77 K
<> over the range of the channel widths and the de bias fields
<> studied here.
<> KP: PHONON INTERACTION, HETEROSTRUCTURES, SCATTERING
<>
<> (207) TI: SPECTRUM OF A NEAR-SURFACE EXCITON INTERACTING WITH PHONONS IN
<> A DOUBLE-HETEROSTRUCTURE AT LOW-TEMPERATURES
<> AU: VAL_AD, ZHARKOI_VP, PAZYUK_VV, TKACH_NV
<> NA: FEDKOVICH STATE UNIV,UL KOTSYUBINSKOGO 2,UA-274012
<> CHERNOVTSY,UKRAINE
<> JN: INORGANIC MATERIALS, 1996, Vol.32, No.8, pp.885-888
<> IS: 0020-1685
<> AB: The Hamiltonian of a near-surface exciton interacting with bulk
<> and interface phonons in a system of two contacting crystals
<> was derived in the representation of occupation numbers for all
<> system variables. The shift of the ground state and the half
<> width of the exciton absorption band were calculated as a
<> function of temperature.
<> KP: BILAYER SYSTEMS
<>
<> (208) TI: QUANTUM CONFINEMENT OF EMBEDDED COPPER CLUSTER SANDWICHED BY
<> LITHIUM-FLUORIDE
<> AU: WANG_GH, ZHANG_HQ, MA_JX, HAN_M, WANG_Q, ZHAO_JJ
<> NA: NANJING UNIV,DEPT PHYS,NANJING 210093,PEOPLES R CHINA
<> NANJING UNIV,NATL LAB SOLID STATE MICROSTRUCT,NANJING
<> 210093,PEOPLES R CHINA
<> CTR ADV STUDIES SCI & TECHNOL MICROSTRUCT,NANJING
<> 210093,PEOPLES R CHINA
<> JN: SURFACE REVIEW AND LETTERS, 1996, Vol.3, No.1, pp.1143-1146
<> IS: 0218-625X
<> AB: Optical absorption and laser Raman scattering spectroscopies as
<> well as EXAFS are used to investigate the copper clusters
<> embedded in the lithium fluoride, and the results indicate that
<> (i) the metal clusters of about 2 nm in diameter have the bulk-
<> like fee structure with a contracted interatomic distance and
<> lower mean coordination number, (ii) the embedded metal
<> clusters show a surface-plasmon resonance, (iii) for clusters
<> smaller than certain size the surface-phonon mode becomes
<> important, and the high-order longitudinal phonon vibrational
<> modes emerge.
<> KP: ELECTRON
<>
<> (209) TI: REMOTE-IMPURITY SCATTERING IN ALINAS/GAINAS FETS
<> AU: RIDLEY_BK
<> NA: UNIV ESSEX,DEPT PHYS,COLCHESTER CO34 3SQ,ESSEX,ENGLAND
<> JN: SEMICONDUCTOR SCIENCE AND TECHNOLOGY, 1996, Vol.11, No.9,
<> pp.1339-1345
<> IS: 0268-1242
<> AB: Theoretical models of remote-impurity, polar-optical phonon and
<> alloy scattering have been applied to an FET structure
<> consisting of AlInAs barriers and GaInAs well lattice-matched
<> to InP, and their predictions of room-temperature mobilities
<> for two occupied subbands compared with experimental data.
<> Three models of remote-impurity scattering were considered.
<> These were the normal model, in which each donor is deemed to
<> scatter independently of the others, the statistical-screening
<> model, in which the interaction is limited to the nearest
<> impurity, and the dipole model, in which only dipole-like
<> fluctuations from a regular array cause scattering. All models
<> predict low mobilities for the electrons in the second subband.
<> The statistical-screening model satisfactorily accounts for the
<> variation of Hall mobility with spacer thickness. The
<> mobilities predicted for polar-optical and alloy scattering
<> were much higher than those observed. It was concluded that the
<> room-temperature mobility was determined by charged-impurity
<> scattering and by interface-roughness scattering.
<> KP: INVERSION LAYERS, HETEROSTRUCTURES, MOBILITY
<>
<> (210) TI: POLAR OPTICAL OSCILLATIONS IN COUPLED QUANTUM-WELLS - THE
<> ELECTRON-PHONON INTERACTION AND SCATTERING
<> AU: SHI_JJ, PAN_SH
<> NA: CHINESE CTR ADV SCI & TECHNOL,WORLD LAB,POB 8730,BEIJING
<> 100080,PEOPLES R CHINA
<> CHINESE ACAD SCI,INST PHYS,BEIJING 100080,PEOPLES R CHINA
<> HENAN NORMAL UNIV,DEPT PHYS,XINXIANG,HENAN,PEOPLES R CHINA
<> JN: JOURNAL OF APPLIED PHYSICS, 1996, Vol.80, No.7, pp.3863-3875
<> IS: 0021-8979
<> AB: Within the framework of the dielectric continuum model, optical
<> phonon modes and their interaction and scattering with
<> electrons in general coupled quantum wells (GCQWs) are studied.
<> The dispersion relation of interface phonons and the electron-
<> interface-phonon coupling strengths as functions of coordinate
<> z and wave-number k are derived and illustrated. We find that
<> the forbidden-frequency behavior of asymmetric heterostructures
<> exists in GCQWs, which may cause an obvious polarization and
<> interaction with electrons. The scattering rates as functions
<> of quantum well parameters are calculated and numerical
<> examples are given graphically. It is shown that the behaviors
<> of intersubband scattering rates are much more complicated than
<> those of intrasubband scattering ones. The results are useful
<> for subsequent theoretical modeling of optical or transport
<> experiments. (C) 1996 American Institute of Physics.
<> KP: INTERSUBBAND TRANSITIONS, GAAS/ALAS SUPERLATTICES, DOUBLE
<> HETEROSTRUCTURE, INTERFACE PHONONS, RAMAN-SCATTERING,
<> DIELECTRIC SLAB, HALF-SPACE, MODES, CRYSTALS, FIELD
<>
<> (211) TI: INTERFACE-PHONON-ASSISTED TRANSITIONS IN QUANTUM-WELL LASERS
<> AU: STROSCIO_MA
<> NA: USA,RES OFF,POB 12211,RES TRIANGLE PK,NC,27709
<> JN: JOURNAL OF APPLIED PHYSICS, 1996, Vol.80, No.12, pp.6864-6867
<> IS: 0021-8979
<> AB: Interface-phonon-assisted transitions an shown to be important
<> in determining the rates for bound-bound transitions as well as
<> the optimum quantum-well parameters for recently proposed
<> quantum-well lasers including the tunneling injection laser and
<> the quantum cascade laser. In particular, it is demonstrated
<> through the use of the dielectric continuum model for interface
<> and confined phonons that the exploitation of interface-phonon-
<> assisted transitions offers a means of maximizing key
<> transition rates and thus of optimizing the performance of both
<> the tunnel injection laser and the quantum cascade laser.
<> KP: ELECTRON, HETEROSTRUCTURES, MODULATION, SCATTERING, SYSTEMS
<>
<> (212) TI: MAGNETOPHONONS IN SHORT-PERIOD SUPERLATTICES
<> AU: GASSOT_P, GENOE_J, MAUDE_DK, PORTAL_JC, DALTON_KSH, SYMONS_DM,
<> NICHOLAS_RJ, ARISTONE_F, PALMIER_JF, LARUELLE_F
<> NA: CNRS,HIGH FIELD MAGNET LAB,BOITE POSTALE 166,F-38042
<> GRENOBLE,FRANCE
<> INST NATL SCI APPL,F-31077 TOULOUSE,FRANCE
<> UNIV OXFORD,DEPT PHYS,CLARENDON LAB,OXFORD OX1 3PU,ENGLAND
<> FRANCE TELECOM,F-92220 BAGNEUX,FRANCE
<> CNRS,MICROSTRUCT & MICROELECT LAB,F-92220 BAGNEUX,FRANCE
<> JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1996, Vol.54, No.20,
<> pp.14540-14549
<> IS: 0163-1829
<> AB: We report the observation of magnetophonon resonances on the
<> background of the longitudinal magneto-conductance in short-
<> period GaAs/AlAs semiconductor superlattices. Both the GaAs and
<> the AlAs longitudinal optical phonons are observed. We show how
<> the enhancement of the magnetophonon effect with electric field
<> is connected to the shift of the electron distribution towards
<> the high-velocity and low-density-of-states region at the
<> midpoint of the reduced Brillouin zone. The observed
<> temperature dependence can be explained by considering the
<> competition between the phonon population and the electron
<> lifetime. The two superposed series of the GaAs and the AlAs
<> optical phonons are shifted when hydrostatic pressure is
<> applied and the relative strength of each series changes as the
<> Gamma miniband comes closer to the X states.
<> KP: DIMENSIONAL ELECTRON-GAS, NEGATIVE DIFFERENTIAL VELOCITY,
<> CONFINED LO PHONONS, SEMICONDUCTOR SUPERLATTICES, GAAS/ALAS
<> SUPERLATTICES, DOUBLE HETEROSTRUCTURES, MINIBAND TRANSPORT,
<> QUANTUM WELLS, RESONANCE, GAAS
<>
<> (213) TI: Electric-field-dependent intersubband transition via optical
<> phonons in a doped-thin-layer inserted quantum-well structure
<> AU: Gu_BL, Duan_WH, Xiong_SY, Guo_YJ
<> NA: CHINA CTR ADV SCI & TECHNOL,WORLD LAB,POB 8730,BEIJING
<> 100080,PEOPLES R CHINA
<> TSING HUA UNIV,DEPT PHYS,BEIJING 100084,PEOPLES R CHINA
<> JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1996, Vol.54, No.23,
<> pp.16983-16988
<> IS: 0163-1829
<> AB: The scattering due to intersubband transition via optical
<> phonons is investigated for a Si-doped-thin-layer inserted
<> GaxAl1-xAs quantum-well structure under an applied longitudinal
<> electric field. The subband wave functions of electron states
<> are determined by solving the Schrodinger and Poisson equations
<> self-consistently, and the interface phonon modes are obtained
<> by use of the transfer matrices method on the basis of the
<> dielectric continuum model. The dependence of scattering rates
<> on the position and Al content of inserted layer is clearly
<> demonstrated. It is found that intersubband scattering can be
<> modulated greatly by changing the applied field and adjusting
<> the well structure parameters, which may be useful for some
<> device applications.
<> KP: ABSORPTION, SCATTERING, ALXGA1-XAS, GA1-XALXAS, STATES
<>
<> (214) TI: Optical interface phonon in thin layer inserted quantum well
<> structure
<> AU: Gu_BL, Duan_WH, Xiong_SY
<> NA: TSING HUA UNIV,DEPT PHYS,BEIJING 100084,PEOPLES R CHINA
<> JN: CHINESE PHYSICS LETTERS, 1996, Vol.13, No.10, pp.768-771
<> IS: 0256-307X
<> AB: The dependence of optical interface phonon on structure was
<> demonstrated for thin layer inserted GaAlAs quantum well
<> structures. It was found that the dispersion is sensitive to
<> tile Al-content of the inserted layer but almost independent of
<> the position of the layer. The results showed that phonon modes
<> can be modulated by adjusting the well parameters. which is
<> useful for some device applications.
<> KP: SEMICONDUCTOR HETEROSTRUCTURES, INTERSUBBAND TRANSITIONS,
<> ELECTRON, SCATTERING, MODES
<>
<> (215) TI: Magnetopolaron-induced increase of the efficiency in two-LO-
<> phonon Raman scattering from quantum wells
<> AU: Lang_IG, Belitsky_VI, Cantarero_A, Korovin_LI, Pavlov_ST,
<> Cardona_M
<> NA: UNIV VALENCIA,DEPT FIS APLICADA,E-46100 VALENCIA,SPAIN
<> AF IOFFE PHYS TECH INST,ST PETERSBURG 194021,RUSSIA
<> PN LEBEDEV PHYS INST,MOSCOW 117924,RUSSIA
<> MAX PLANCK INST FESTKORPERFORSCH,D-70569 STUTTGART,GERMANY
<> JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1996, Vol.54, No.24,
<> pp.17768-17778
<> IS: 0163-1829
<> AB: The magnetopolaron wave function and energy for resonantly
<> coupled electronic and vibrational excitations in a quantum
<> well are derived and used to evaluate the efficiency of Raman
<> scattering by two LO phonons. A strong increase of the
<> scattering intensity along with the splitting of Raman peaks is
<> predicted in the magnetopolaron regime.
<> KP: MAGNETIC-FIELD, CYCLOTRON-RESONANCE, BULK SEMICONDUCTORS,
<> SUPERLATTICES, ELECTRON, POLARONS
<>
<> (216) TI: Spectrum and the interaction of electron with inertial and
<> noninertial polarizations in spherical semiconducting
<> heterosystem
<> LA: Romanian
<> AU: Tkach_NV, Boichuk_VI, Golovatskii_VA, Voitsekhivskaya_ON
<> NA: CHERNOVTSY STATE UNIV,UA-274012 CHERNOVTSY,UKRAINE
<> JN: FIZIKA TVERDOGO TELA, 1996, Vol.38, No.10, pp.3161-3171
<> IS: 0367-3294
<> KP: OPTICAL-PHONON INTERACTION, QUANTUM-WELLS, EXCITONS, SINGLE,
<> ENERGY
<>
<> (217) TI: Electron-phonon scattering engineering
<> AU: Pozela_J, Juciene_V, Namajunas_A, Pozela_K
<> NA: LITHUANIA ACAD SCI,INST SEMICOND PHYS,LT-232600
<> VILNIUS,LITHUANIA
<> JN: SEMICONDUCTORS, 1997, Vol.31, No.1, pp.69-71
<> IS: 1063-7826
<> AB: We present calculations which show that independent
<> quantization of electrons and phonons allows the intra- and
<> intersubband electron-phonon scattering rate in two-dimensional
<> structures to be changed. It is considered how the design of
<> multi-heterostructure quantum well (QW) changes the electron
<> mobility and population of subbands in the QW. It was shown
<> that the insertion of the phonon wall (a few AlAs monolayers)
<> into an AlAs/GaAs/AlAs double heterostructure allows the
<> electron mobility in the QW to be enhanced and electron
<> intersubband population to be inverted. (C) 1997 American
<> Institute of Physics.
<> KP: QUANTUM-WELLS, HETEROSTRUCTURES, SINGLE, RATES
<>
<> (218) TI: Polar scattering of 2-dimensional electrons in quantum holes.
<> LA: Russian
<> AU: Mirlin_DN, Rodina_AV
<> NA: AF IOFFE PHYS TECH INST,POLITEKHNICHESKAYA 26,ST PETERSBURG
<> 194021,RUSSIA
<> JN: FIZIKA TVERDOGO TELA, 1996, Vol.38, No.11, pp.3201-3211
<> IS: 0367-3294
<> KP: OPTICAL-PHONON INTERACTION, WELL STRUCTURES, MICROSCOPIC
<> CALCULATION, DOUBLE HETEROSTRUCTURES, FROHLICH INTERACTION,
<> SUPERLATTICES, LUMINESCENCE, SYSTEMS, MODES
<>
<> (219) TI: Energy and effective mass of a polaron in asymmetric
<> semiconductor quantum well structures
<> AU: Zhu_XQ, Shi_JJ, Liu_ZX, Pan_SH
<> NA: HENAN NORMAL UNIV,DEPT PHYS,XINXIANG 453002,HENAN,PEOPLES R
<> CHINA
<> CHINESE CTR ADV SCI & TECHNOL,WORLD LAB,BEIJING 100080,PEOPLES
<> R CHINA
<> ACAD SINICA,INST PHYS,BEIJING 100080,PEOPLES R CHINA
<> JN: ZEITSCHRIFT FUR PHYSIK B-CONDENSED MATTER, 1997, Vol.102, No.2,
<> pp.207-216
<> IS: 0722-3277
<> AB: In this paper, the correct electron extended stales wave
<> functions and the density of states in asymmetric single
<> quantum wells (QWs) are given for the first time, we put right
<> mistakes from some previous papers of some other authors.
<> Within the framework of the second-order perturbation theory,
<> the ground-state polaron binding energy and effective mass
<> correction in asymmetric single QWs are studied including the
<> full energy specturm, i.e., the discrete energy levels in the
<> well and the continuum energy spectrum above the barrier, and
<> all possible optical-phonon modes. The effects of the finite
<> electronic confinement potential and the subband
<> nonparabolicity are considered. The relative importance of the
<> different phonon modes is investigated. Our results show that
<> the polaron energy and effective mass are sensitive to the
<> asymmetry of the structure and have a close relation to the
<> interface phonon dispersion. When well width and one side
<> barrier height of asymmetric QWs are fixed and identical with
<> those of symmetric QW, the polaron binding energy and effective
<> mass in asymmetric QWs are always less than those in symmetric
<> QW. It is necessary to include the continuum energy spectrum as
<> intermediate states in the study of polaron effects in QWs in
<> order to obtain the correct results. The subband non-
<> parabolicity has little influence on the polaron effects. The
<> polaron energies given in this paper are excellent agreement
<> with our variational results.
<> KP: ELECTRON-PHONON INTERACTION, INTERFACE-PHONON, MAGNETIC-FIELD,
<> GAAS/ALAS SUPERLATTICES, CYCLOTRON-RESONANCE, DIELECTRIC SLAB,
<> BOUND POLARON, CRYSTAL SLAB, SELF-ENERGY, MODES
<>
<> (220) TI: Electron mobility and subband population tuning by a phonon
<> wall inserted in a semiconductor quantum well
<> AU: Pozela_J, Juciene_V, Namajunas_A, Pozela_K
<> NA: LITHUANIA ACAD SCI,INST SEMICOND PHYS,ICSC WORLD LAB,LITHUANIAN
<> BRANCH,GOSTAUTO 11,LT-232600 VILNIUS,LITHUANIA
<> JN: JOURNAL OF APPLIED PHYSICS, 1997, Vol.81, No.4, pp.1775-1780
<> IS: 0021-8979
<> AB: The electron-optical phonon scattering rate and electron
<> subband population in a semiconductor quantum well (QW)
<> containing a phonon wall (Ph-wall) is calculated. It is shown
<> that the Ph-wall (a barrier of one-two AlAs monolayers)
<> inserted into an AlAs/GaAs/AlAs QW changes radically the intra-
<> and intersubband scattering rates. Electron subband energy
<> spectra, phonon frequencies, electron and phonon wave functions
<> and scattering rates are found to depend on the Ph-wall
<> position in the QW. The largest decrease of the intrasubband
<> electron-phonon scattering rate takes place when the Ph-wall is
<> located at the QW center. The intersubband scattering rate
<> increases resonantly when the intersubband energy separation is
<> equal to the interface phonon energy. The Ph-wall increases the
<> electron mobility in the QW except the areas where the
<> resonance scattering takes place. The Ph-wall position in the
<> QW causing the subband population inversion is determined in
<> the case of optical excitation. (C) 1997 American Institute of
<> Physics.
<> KP: SCATTERING RATES, EMISSION, HETEROSTRUCTURES, SINGLE
<>
<> (221) TI: Polaron effects in asymmetric semiconductor quantum-well
<> structures
<> AU: Shi_JJ, Zhu_XQ, Liu_ZX, Pan_SH, Li_XY
<> NA: HENAN NORMAL UNIV,DEPT PHYS,XINXIANG 453002,HENAN,PEOPLES R
<> CHINA
<> CHINA CTR ADV SCI & TECHNOL,WORLD LAB,BEIJING 100080,PEOPLES R
<> CHINA
<> CHINESE ACAD SCI,INST PHYS,BEIJING 100080,PEOPLES R CHINA
<> JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1997, Vol.55, No.7,
<> pp.4670-4679
<> IS: 0163-1829
<> AB: In this paper, polaron effects in asymmetric quantum-well
<> structures (QW's) are investigated by using second-order
<> perturbation theory and the modified Lee-Low-Pines (LLP)
<> variational method. By applying the Green's-function method,
<> explicit analytical expressions for the electron extended-state
<> wave functions and the density of states in a general step QW's
<> are given. Within the framework of second-order perturbation
<> theory, the ground-state polaron binding energy and effective
<> mass in step and asymmetric single QW's are studied as due to
<> the interface optical phonons, confined bulklike LO and half-
<> space LO phonons. The full energy spectrum is included in our
<> calculations. The effects of the finite electronic confinement
<> potential and the subband nonparabolicity are also considered.
<> The relative importance of the different phonon modes is
<> analyzed. By means of the modified LLP variational method, the
<> binding energy of a polaron confined to asymmetric single QW's
<> is also investigated. Our results show that in ordinary
<> asymmetric QW's, the asymmetry of the QW's has a significant
<> influence on the polaron effect, which has a close relationship
<> to the interface phonon dispersion. When the well width and one
<> side barrier height of asymmetric single QW's are fixed and
<> identical with those of symmetric QW's, the polaron binding
<> energy in asymmetric QW's is always smaller than that in
<> symmetric QW's. We have also found that it is necessary to
<> include the continuum energy spectrum as intermediate states in
<> the perturbation calculations in order to obtain the correct
<> results; the subband nonparabolicity has a small influence on
<> the polaron effect. Comparing our results obtained by using two
<> different methods, good agreement is found.
<> KP: INTERFACE-PHONON INTERACTION, MAGNETIC-FIELD, CYCLOTRON-
<> RESONANCE, BOUND POLARON, CRYSTAL SLAB, SELF-ENERGY, ELECTRON,
<> SCATTERING, MAGNETOPOLARON, SINGLE
<>
<> (222) TI: Energy relaxation via confined and interface phonons in
<> quantum-wire systems
<> AU: Bennett_CR, Tanatar_B
<> NA: UNIV ESSEX,DEPT PHYS,COLCHESTER CO4 3SQ,ESSEX,ENGLAND
<> BILKENT UNIV,DEPT PHYS,TR-06533 BILKENT,TURKEY
<> JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1997, Vol.55, No.11,
<> pp.7165-7169
<> IS: 0163-1829
<> AB: We present a fully dynamical and finite temperature study of
<> the hot-electron momentum relaxation rate and the power loss in
<> a coupled system of electrons and confined and interface
<> phonons in a quantum-wire structure. Renormalization effects
<> due to electron-phonon interactions lead to an enhancement in
<> the power loss similar to the bulk phonon case.
<> KP: HOT-ELECTRON RELAXATION, COUPLED-MODE CONTRIBUTIONS, CARRIER
<> RELAXATION, GAAS, SEMICONDUCTOR, EXCITATIONS, SCATTERING,
<> EMISSION, WELLS, ALAS
<>
<> (223) TI: Electron-phonon interaction in a cylindrical quantum dot
<> AU: Li_WS, Chen_CY
<> NA: HONG KONG POLYTECH UNIV,DEPT ELECT ENGN,HONG KONG,HONG KONG
<> HONG KONG POLYTECH UNIV,DEPT ELECT ENGN,HONG KONG,HONG KONG
<> GUANGZHOU NORMAL UNIV,DEPT PHYS,GUANGZHOU 510400,PEOPLES R
<> CHINA
<> JN: PHYSICA B, 1997, Vol.229, No.3-4, pp.375-382
<> IS: 0921-4526
<> AB: The confined logitudinal-optical (LO) phonon and surface-
<> optical (SO) phonon modes of a free-standing cylindrical
<> quantum dot are discussed within the dielectric continuum
<> approximation. It is found that there exist two types of SO
<> phonon modes: top SO (TSO) mode and side SO (SSO) in a
<> cylindrical quantum dot. The operators describing the free
<> phonon modes and their interactions with electrons in the
<> system are also derived.
<> KP: LO PHONONS, SPECTROSCOPY, EXCITONS, INGAAS, DEPENDENCE, FIELD,
<> MODES, WELLS, WIRES
<> WA: electron-phonon interaction, quantum dot
<>
<> (224) TI: Phonon dispersion and electron-polar optical phonon interaction
<> in coupled quantum-well structures in the modified image-charge
<> ansatz approach
<> AU: Wang_J, Leburton_JP, Pozela_J
<> NA: UNIV ILLINOIS,BECKMAN INST ADV SCI & TECHNOL,URBANA,IL,61801
<> UNIV ILLINOIS,CTR COMPOUND SEMICOND MICROELECT,URBANA,IL,61801
<> ICSC,WORLD LAB,INST SEMICOND PHYS,VILNIUS,LITHUANIA
<> JN: JOURNAL OF APPLIED PHYSICS, 1997, Vol.81, No.8 Pt1, pp.3468-
<> 3473
<> IS: 0021-8979
<> AB: Phonon dispersion and Frohlich interaction in coupled quantum-
<> well structures are derived by using a modified image-charge
<> ansatz that shows that I-he mode symmetry in the surface phonon
<> dispersion of single quantum-well (QW) structures is modified
<> by the addition of a thin inner barrier. The electron-phonon
<> scattering rates are evaluated for phonons in the entire
<> coupled QW configuration and compared with the corresponding
<> rates calculated for phonons in the separated-single QW
<> approximation. Our calculations show that the separated-single
<> QW phonon model provides reasonable estimates of the electron-
<> phonon scattering fates except for intersubband processes when
<> the quantized energy separation between the initial and final
<> electron states is in resonance with the polar optical phonon
<> energy. (C) 1997 American Institute of Physics.
<> KP: DOUBLE HETEROSTRUCTURES, HARMONIC-GENERATION, INTERFACE PHONONS,
<> SCATTERING RATES
<>
<> (225) TI: Nonlinear transport in GaAs/AlAs harmonically confined quantum
<> wires
<> AU: Lima_ICD, Wang_XF, Lei_XL
<> NA: UNIV ESTADO RIO DE JANEIRO,INST FIS,RUA SAO FRANCISCO XAVIER
<> 524,BR-20550013 RIO JANEIRO,BRAZIL
<> UNIV SAO FRANCISCO,FAC ENGN,BR-13257900 ITATIBA,SP,BRAZIL
<> ACAD SINICA,SHANGHAI INST MET,SHANGHAI 200050,PEOPLES R CHINA
<> JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1997, Vol.55, No.16,
<> pp.10681-10687
<> IS: 0163-1829
<> AB: The linear and nonlinear resistivities of GaAs/AlAs quantum
<> wires under an applied magnetic field normal to the interfaces
<> are obtained using the balance equation technique. Inelastic
<> scattering by optic-confined and interface vibrational modes
<> are analyzed. The observed sharp peaks in the linear
<> resistivity showing phonon resonances in the scattering by bulk
<> modes is broadened if this scattering is due to the GaAs
<> confined modes. On the other hand, the AlAs-like interface
<> modes add new peaks to the resistivity. The electron cooling
<> effect is weakened at the magnetophonon resonance due to the
<> greatly enhanced intersubband transition.
<> KP: ONE-DIMENSIONAL CHANNELS, STRONG ELECTRIC-FIELD, LO-PHONON-
<> SCATTERING, SUPERLATTICES, WELLS, RESONANCE
<>
<> (226) TI: New polaron effect in magnetooptic phenomena in a quantum well
<> AU: Korovin_LI, Lang_IG, Pavlov_ST
<> NA: AF IOFFE PHYS TECH INST,POLITEKHNICHESKAYA 26,ST PETERSBURG
<> 194021,RUSSIA
<> PN LEBEDEV PHYS INST,MOSCOW 1179924,RUSSIA
<> JN: JETP LETTERS, 1997, Vol.65, No.7, pp.532-536
<> IS: 0021-3640
<> AB: It is predicted that resonance coupling between two discrete
<> electron energy levels corresponding to different size-
<> quantization quantum numbers and different Landau quantum
<> numbers can occur in a quantum well in a quantizing magnetic
<> field. The resonance coupling is due to the interaction of an
<> electron with LO phonons and results in the formation of
<> polaron states of a new type. It is shown that for a certain
<> value of the magnetic field, which depends on the splitting of
<> the electron size-quantization levels, the absorption peak and
<> the two-phonon resonance Raman scattering peak split into two
<> components, the separation between which is determined by the
<> electron-phonon coupling constant. The resonance coupling
<> between size-quantization levels with the same Landau quantum
<> numbers is also studied. The splitting of the peaks in this
<> case is virtually independent of the magnetic field and can be
<> observed in much weaker fields. The experimental observation of
<> the effect will make it possible to determine the relative
<> position of the electronic levels and the electron-phonon
<> coupling constant. (C) 1997 American Institute of Physics.
<> KP: PHONON INTERACTION, MAGNETIC-FIELD, ELECTRON
<>
<> (227) TI: Gamma-X hybridization effects on the carrier subband transition
<> times in type I GaAs-AlAs quantum wells
<> AU: Lima_ICD, Weber_G, Reinecke_TL
<> NA: UNIV SAO FRANCISCO,FAC ENGN,BR-13251900 ITATIBA,SP,BRAZIL
<> UNIV ESTADO RIO DE JANEIRO,INST FIS,BR-20550013 RIO
<> JANEIRO,BRAZIL
<> USN,RES LAB,WASHINGTON,DC,20375
<> JN: SOLID STATE COMMUNICATIONS, 1997, Vol.102, No.11, pp.799-802
<> IS: 0038-1098
<> AB: We calculate the Gamma - Gamma carrier scattering times due to
<> emission of confined and interface optic phonons taking into
<> account the Gamma-X hybridization of the electron states for
<> type I GaAs/AlAs quantum well structures. We show that the
<> intersubband transition times increase for well widths where
<> the second GaAs electron subband becomes dose in energy to the
<> X point of the AlAs barrier and that this increase is strongly
<> dependent on the amount of hybridization. These results
<> suggests that the hybridization may affect carrier transport
<> and relaxation and that intersubband scattering times could be
<> used for measuring the hybridization of the second electron
<> subband. (C) 1997 Elsevier Science Ltd.
<> KP: SHORT-PERIOD SUPERLATTICES, PHONON SCATTERING RATES, SPACE
<> CHARGE-TRANSFER, ENVELOPE FUNCTIONS, SEMICONDUCTOR
<> HETEROINTERFACES, CONFINED PHONONS, BINDING-ENERGY, GAAS/ALAS,
<> CONNECTION, EMISSION
<>
<> (228) TI: Electron-phonon interaction in spherical multilayer
<> nanoheterostructures
<> AU: Tkach_NV
<> NA: CHERNOVTSY STATE UNIV,UA-274012 CHERNOVTSY,UKRAINE
<> JN: PHYSICS OF THE SOLID STATE, 1997, Vol.39, No.6, pp.995-999
<> IS: 1063-7834
<> AB: The complete hamiltonian of an electron-phonon system in the
<> second quantization representation for a complex spherical
<> nanoheterostructure with an arbitrary number of semiconducting
<> layers is obtained in a polarized continuum model for bounded
<> volume and interface phonons. The energy of the electron ground
<> state is calculated using the experimentally realized
<> CdS/HgS/H2O system as an example. The cause of the nonmonotonic
<> dependence of the shift in the electron ground state on the HgS
<> thickness is established as due to the interaction with bounded
<> phonons. (C) 1997 American Institute of Physics.
<> KP: QUANTUM-WELLS, EXCITONS
<>
<> (229) TI: Resonant tunneling transistor characteristics using a Fabry-
<> Perot resonator
<> AU: Lee_C
<> NA: HONAM UNIV,DEPT ELECT ENGN,KWANGJU 506090,SOUTH KOREA
<> JN: JOURNAL OF THE KOREAN PHYSICAL SOCIETY, 1997, Vol.31, No.1,
<> pp.112-116
<> IS: 0374-4884
<> AB: Resonant tunneling characteristics due to the reduced size of
<> semiconductor devices are theoretically studied. Particularly,
<> we investigate the current-voltage curve of resonant tunneling
<> three-terminal electron devices. We obtain the wave amplitudes
<> in a Fabry-Perot resonator by using cascading matrices. We find
<> that inelastic scattering is an important effect that strongly
<> reduces the probability for coherent tunneling. As a result,
<> the valley current is increased by incoherent tunneling.
<> KP: HETEROSTRUCTURES
<>
<> (230) TI: Polaron in a superlattice with delta-like potentials
<> AU: Guseinov_NM, Gashimzade_NF, Gadzhiev_AT
<> NA: AZERBAIJAN ACAD SCI,INST PHYS,BAKU 370143,AZERBAIJAN
<> JN: PHYSICS OF THE SOLID STATE, 1997, Vol.39, No.1, pp.158-161
<> IS: 1063-7834
<> AB: The problem of the polaron spectrum is studied in a
<> superlattice having narrow quantum wells and relatively wide
<> potential barriers. A delta-like superlattice potential is
<> chosen to solve the problem. This model is adequate, if the
<> penetration depth of the electron wave function into the
<> barrier region is much greater than the width of the quantum
<> well. A weak-coupling polaron at low temperature is studied.
<> Only volume phonons are considered. Expressions are obtained
<> for the polaron mass and the shift of the polaron energy under
<> these assumptions. To test the model, numerical calculations
<> were performed for an InAs-GaSb superlattice, whose quantum
<> wells are quite deep (the energy offset of the conduction bands
<> in InAs and GaSb equals 830 meV), narrow (the width of a
<> quantum well corresponds to the width of an InAs monolayer 6
<> Angstrom), and the barrier width corresponding to the thickness
<> of the GaSb layers equals 150 Angstrom. The assumption that the
<> penetration depth of the wave function is much greater than the
<> barrier width holds well. (C) 1997 American Institute of
<> Physics.
<>
<> (231) TI: Simulation of carrier capture in semiconductor quantum wells:
<> Bridging the gap from quantum to classical transport
<> AU: Register_LF, Hess_K
<> NA: UNIV ILLINOIS,BECKMAN INST,URBANA,IL,61801
<> UNIV ILLINOIS,COORDINATED SCI LAB,URBANA,IL,61801
<> JN: APPLIED PHYSICS LETTERS, 1997, Vol.71, No.9, pp.1222-1224
<> IS: 0003-6951
<> AB: The effects of lost phase coherence on carrier capture by
<> semiconductor quantum wells are simulated using Schrodinger
<> Equation Monte Carlo. Results are shown for polar-optical-
<> phonon-induced capture of both electrons and holes, and for
<> both monoenergetic and thermal distributions of incident charge
<> carriers. Results suggest that semiclassical modeling of hole
<> capture may be sufficient, provided that quantum mechanical
<> reflection from the individual heterointerfaces still is taken
<> into account, However, for a quantum well laser optimized to
<> operate at an electron capture resonance, semiclassical
<> calculations blind to the resonance structure would
<> underestimate the capture rate, while Golden-Rule calculations,
<> which assume complete phase coherence, could somewhat
<> overestimate it. (C) 1997 American Institute of Physics.
<>
<> (232) TI: Influence of complex phonon spectra on intersubband optical
<> gain
<> AU: Kisin_MV, Gorfinkel_VB, Stroscio_MA, Belenky_G, Luryi_S
<> NA: SUNY STONY BROOK,DEPT ELECT ENGN,STONY BROOK,NY,11794
<> USA,RES OFF,RES TRIANGLE PK,NC,27709
<> SUNY STONY BROOK,DEPT ELECT ENGN,STONY BROOK,NY,11794
<> JN: JOURNAL OF APPLIED PHYSICS, 1997, Vol.82, No.5, pp.2031-2038
<> IS: 0021-8979
<> AB: Electron-phonon scattering rates and intersubband optical gain
<> spectra were calculated, including the optical phonon
<> confinement effect in AlGaAs/GaAs/AlGaAs quantum well
<> heterostructures. Comparison of the calculated gain spectra
<> with those calculated using the bulk phonon approximation shows
<> that details of the phonon spectrum have a strong influence on
<> the intersubband optical gain. (C) 1997 American Institute of
<> Physics.
<> KP: QUANTUM-WELLS, WAVE-FUNCTION, BOUNDARY-CONDITIONS, KANE MODEL,
<> LASER, HETEROSTRUCTURES, TRANSITIONS, RELAXATION, SCATTERING,
<> SINGLE
<>
<> (233) TI: Density of states and phonon-induced relaxation of electrons in
<> semiconductor quantum dots
<> AU: Inoshita_T, Sakaki_H
<> NA: JST,QUANTUM TRANSIT PROJECT,MEGURO KU,4-7-6-4F KOMABA,TOKYO
<> 153,JAPAN
<> UNIV TOKYO,RCAST,MEGURO KU,TOKYO 153,JAPAN
<> JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1997, Vol.56, No.8,
<> pp.R4355-R4358
<> IS: 0163-1829
<> AB: To understand the energy relaxation of electrons interacting
<> with both longitudinal-optical (LO) and longitudinal-acoustic
<> (LA) phonons in a semiconductor quantum dot, the electron
<> density-of-states D(E) is calculated using the Green's-function
<> method taking into account interactions of all orders and self-
<> consistent level broadening. The D(E) calculated for a GaAs dot
<> exhibits sharp peaks (width less than or similar to 0.1 meV) at
<> T=77 K, indicating the absence of fast relaxation in the usual
<> sense. For level separation near, but not necessarily too close
<> to, the LO-phonon energy, the peaks are equally narrow but
<> split by the coherent mixing of electron levels (Rabi
<> splitting). The LA phonons are much too weak to destroy this
<> coherence. In the time domain, the electron undergoes rapid (<
<> ps) Rabi flopping between levels.
<> KP: SUPERLATTICES, SCATTERING, SYSTEMS, WELLS
<>
<> (234) TI: Triple magnetopolarons in quantum wells
<> AU: Lang_IG, Belitsky_VI, Cantarero_A, Korovin_LI, Pavlov_ST,
<> Cardona_M
<> NA: UNIV VALENCIA,DEPT FIS APLICADA,E-46100 VALENCIA,SPAIN
<> RUSSIAN ACAD SCI,AF IOFFE PHYSICOTECH INST,ST PETERSBURG
<> 194021,RUSSIA
<> PN LEBEDEV PHYS INST,MOSCOW 117924,RUSSIA
<> MAX PLANCK INST FESTKORPERFORSCH,D-70569 STUTTGART,GERMANY
<> JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1997, Vol.56, No.11,
<> pp.6880-6888
<> IS: 0163-1829
<> AB: We derive the equations for eigenstates and eigenenergies of a
<> triple magnetopolaron in quantum-well structures. An iteration
<> procedure for obtaining the wave function and energy including
<> the contributions of diagrams with crossing phonon lines is
<> given. We show that under conditions of exact resonance the
<> middle energy branch of the triply split magnetopolaron state
<> consists of only two out of three bare states. We suggest the
<> experimental verification of this prediction.
<> KP: NONPARABOLICITY, GAAS
<>
<> (235) TI: Mobility calculation of quasi-two-dimensional electron gas by
<> the energy loss method
<> AU: Asatrian_AL, Vartanian_AL, Kirakosian_AA
<> NA: YEREVAN STATE UNIV,FAC PHYS,AL MANOOGIAN 1,YEREVAN
<> 375049,ARMENIA
<> JN: PHYSICA STATUS SOLIDI B-BASIC RESEARCH, 1997, Vol.203, No.1,
<> pp.169-178
<> IS: 0370-1972
<> AB: The energy loss method for mobility calculation in low-
<> dimensional semiconductor structures with quasi-two-dimensional
<> gas of charge carriers is developed. For scattering by charged
<> impurities a mobility expression is found which depends on
<> quantum well characteristics, the form of the impurity center
<> distribution within a well and surroundings, and also on the
<> dielectric constant of the system under consideration. The
<> method is also used for mobility calculation in the case of
<> interface roughness and alloy disorder scattering in a quantum
<> well. It is shown that taking account of interface roughness
<> scattering at near to room temperature improves considerably
<> the agreement between the theory and experiment.
<> KP: INTERFACE ROUGHNESS SCATTERING, QUANTUM-WELL HETEROSTRUCTURE,
<> PHONON-SCATTERING, TRANSPORT, SINGLE, FIELD
<>
<> (236) TI: Exciton-photon interaction effects in quantum wells
<> AU: Zheng_RS, Matsuura_M
<> NA: YAMAGUCHI UNIV,FAC ENGN,DEPT ADV MAT SCI & ENGN,UBE,YAMAGUCHI
<> 755,JAPAN
<> INNER MONGOLIA UNIV,DEPT PHYS,HOHHOT,PEOPLES R CHINA
<> YAMAGUCHI UNIV,FAC ENGN,DEPT ADV MAT SCI & ENGN,UBE,YAMAGUCHI
<> 755,JAPAN
<> JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1997, Vol.56, No.4,
<> pp.2058-2061
<> IS: 0163-1829
<> AB: Properties of excitons interacting with interface optical
<> phonons and confined longitudinal optical phonons in
<> semiconducting compound quantum wells are investigated
<> theoretically. By using the nonseparable trial wave function
<> the exciton binding energies and the interaction energies of
<> excitons with every phonon mode in two typical quantum-well
<> structures. GaAs/AlAs and CdSe/ZnSe, are calculated as a
<> function of the well width. Some interesting features of the
<> exciton-phonon interaction system in quantum wells are found
<> and discussed. The theoretical result gives a reasonable
<> explanation of the agreement of some simple exciton theories
<> with experiments.
<> KP: OPTICAL-PHONON, BINDING-ENERGY, DOUBLE HETEROSTRUCTURES,
<> WANNIER EXCITONS, MAGNETIC-FIELD, CONFINEMENT, ABSORPTION,
<> STATES, SYSTEM, MASS
<>
<> (237) TI: Hot-phonon effects on electron runaway from GaAs quantum wires
<> AU: Paulavicius_G, Mickevicius_R, Mitin_V, Stroscio_MA
<> NA: WAYNE STATE UNIV,DEPT ELECT & COMP ENGN,DETROIT,MI,48202
<> USA,RES OFF,RES TRIANGLE PK,NC,27709
<> JN: JOURNAL OF APPLIED PHYSICS, 1997, Vol.82, No.7, pp.3392-3395
<> IS: 0021-8979
<> AB: Nonequilibrium (hot) optical phonon effects on electron runaway
<> from GaAs quantum wires embedded in AlGaAs have been
<> investigated by Monte Carlo technique. We have simulated the
<> carrier runaway kinetics in the 0 range for a lattice temperature of 30 K. Due to optical phonon
<> mode confinement by GaAs/AlGaAs heterointerfaces, the buildup
<> of generated hot phonons is strongly pronounced in the quantum
<> wires. Even at moderate electron concentrations and electric
<> fields, the accumulation of these phonons may become
<> significant and substantially affect all transport properties
<> in the structure. As a result of reduced hot electron cooling
<> rates in the presence of nonequilibrium optical phonons, the
<> high-energy tail of the carrier distribution function extends
<> above the potential barriers at the quantum wire boundaries.
<> This may eventually lead to significant electron escape from
<> the potential well, even at relatively low electric fields,
<> what significantly affects the performance of such nanoscale
<> systems. (C) 1997 American Institute of Physics.
<> KP: CASCADE LASER, SCATTERING, TRANSISTORS, TRANSPORT, DYNAMICS,
<> LIMIT
<>
<> (238) TI: Transfer matrix method for interface optical-phonon modes in
<> multiple-interface heterostructure systems
<> AU: Yu_SG, Kim_KW, Stroscio_MA, Iafrate_GJ, Sun_JP, Haddad_GI
<> NA: N CAROLINA STATE UNIV,DEPT ELECT & COMP ENGN,RALEIGH,NC,27695
<> USA,RES OFF,RES TRIANGLE PK,NC,27709
<> UNIV MICHIGAN,DEPT ELECT ENGN & COMP SCI,ANN ARBOR,MI,48109
<> N CAROLINA STATE UNIV,DEPT PHYS,RALEIGH,NC,27695
<> JN: JOURNAL OF APPLIED PHYSICS, 1997, Vol.82, No.7, pp.3363-3367
<> IS: 0021-8979
<> AB: Interactions of carriers with interface optical phonons
<> dominate over other carrier-phonon scatterings in narrow
<> quantum-well structures. Herein, a transfer matrix method is
<> used to establish a formalism for determining the dispersion
<> relations, electrostatic potentials, and Frohlich interaction
<> Hamiltonians of the interface optical phonons for multiple-
<> interface heterostructure systems within the framework of the
<> macroscopic dielectric continuum model. This method facilitates
<> systematic calculations for complex structures where the
<> conventional method is very difficult to implement. Several
<> specific cases are treated to illustrate the advantages of the
<> general formalism. (C) 1997 American Institute of Physics.
<> KP: QUANTUM-WELLS, ELECTRONIC POLARIZABILITY, SUPERLATTICES,
<> SCATTERING, LASERS, GAAS, ALAS
<>
<> (239) TI: Polaron ground state in quantum wells of II-VI compounds
<> AU: Liang_SD, Chen_CY, Xie_HJ, Lin_DL
<> NA: GUANGZHOU NORMAL UNIV,DEPT PHYS,GUANGZHOU 510400,PEOPLES R
<> CHINA
<> UNIV HONG KONG,DEPT PHYS,HONG KONG,HONG KONG
<> SUNY BUFFALO,DEPT PHYS,BUFFALO,NY,14260
<> JN: CHINESE JOURNAL OF PHYSICS, 1997, Vol.35, No.5, pp.584-594
<> IS: 0577-9073
<> AB: Ground state properties of a polaron in II-VI quantum wells are
<> investigated by considering both the confined and interface
<> phonon modes which exist in such structures. The Landau-Pekar
<> approach is employed to treat the electron-phonon interaction
<> because these materials are generally much more ionic than III-
<> V compounds. The binding energy and effective mass are
<> calculated by means of a variational method as functions of the
<> well width, and the three-dimensional limits in both the well
<> and barrier materials are examined. Contributions from
<> different phonon modes are studied separately and our results
<> demonstrate the importance of symmetric interface modes in
<> wells of widths similar to 100 Angstrom or less.
<> KP: STRONG-COUPLING THEORY, DOUBLE HETEROSTRUCTURE, CYCLOTRON-
<> RESONANCE, PHONON INTERACTION, INTERFACE POLARON, MAGNETIC-
<> FIELD, BOUND POLARON, MAGNETOPOLARONS, SUPERLATTICES, CRYSTALS
<>
<> (240) TI: Exciton-phonon interaction in the spherical nanoheterosystem
<> CdS/beta-HgS/H2O
<> AU: Tkach_M, Holovatsky_V, Voitsekhivska_O, Mikhalyova_M
<> NA: CHERNIVTSI STATE UNIV,CHERNOVTSY,UKRAINE
<> JN: PHYSICA STATUS SOLIDI B-BASIC RESEARCH, 1997, Vol.203, No.2,
<> pp.373-386
<> IS: 0370-1972
<> AB: The theoretical investigation of the electron. hole and phonon
<> spectra in the spherical nanoheterosystem CdS/beta-HgS/H2O is
<> performed within the effective mass approximation in the
<> dielectric continuum model. The Hamiltonian of the exciton-
<> phonon system is established in the representation of second
<> quantization. The energy of the exciton basic state (E-ex)
<> renormalized due to the interaction with phonons is obtained.
<> The existence of a crook in the E-ex curve depending on the
<> (beta-HgS shell thickness is proved and explained. A
<> satisfactory correlation between the theoretical and
<> experimental results is obtained.
<> KP: ZERO-DIMENSIONAL STRUCTURES, QUANTUM, SPECTRUM, GAAS/ALAS,
<> SYSTEMS
<>
<> (241) TI: Resonant magnetopolaron effects due to interface phonons in
<> GaAs/AlGaAs multiple quantum well structures
<> AU: Wang_YJ, Nickel_HA, McCombe_BD, Peeters_FM, Shi_JM, Hai_GQ,
<> Wu_XG, Eustis_TJ, Schaff_W
<> NA: FLORIDA STATE UNIV,NATL HIGH MAGNET LAB,TALLAHASSEE,FL,32306
<> SUNY BUFFALO,DEPT PHYS,BUFFALO,NY,14260
<> UNIV ANTWERP,DEPT NAT KUNDE,B-2610 ANTWERP,BELGIUM
<> UNIV FED SAO CARLOS,DEPT FIS,BR-13565905 SAO CARLOS,SP,BRAZIL
<> CHINESE ACAD SCI,INST SEMICOND,NATL LAB SUPERLATT &
<> MICROSTRUCT,BEIJING 100083,PEOPLES R CHINA
<> CORNELL UNIV,DEPT ELECT ENGN,ITHACA,NY,14853
<> JN: PHYSICAL REVIEW LETTERS, 1997, Vol.79, No.17, pp.3226-3229
<> IS: 0031-9007
<> AB: Polaron cyclotron resonance (CR) has been studied in three
<> modulation-doped GaAs/Al0.3Ga0.7As multiple quantum well
<> structures in magnetic field up to 30 T. Large avoided-level-
<> crossing splittings of the CR near the GaAs reststrahlen
<> region, and smaller splittings in the region of the AlAs-like
<> optical phonons of th AlGaAs barriers, are observed. Based on a
<> comparison with a detailed theoretical calculation, the high
<> frequency splitting, the magnitude of which increases with
<> decreasing well width, is assigned to resonant polaron
<> interactions with AlAs-like interface phonons.
<> KP: POLARON-CYCLOTRON-RESONANCE, GAAS, HETEROSTRUCTURES, MODES,
<> HETEROJUNCTIONS, SUPERLATTICES, ELECTRONS, MASS
<>
<> (242) TI: Exciton-phonon interaction in fractional dimensional space
<> AU: Thilagam_A
<> NA: NO TERR UNIV,FAC SCI,DARWIN,NT 0909,AUSTRALIA
<> JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1997, Vol.56, No.15,
<> pp.9798-9804
<> IS: 0163-1829
<> AB: Explicit analytical expressions of Frohlich-like Hamiltonians
<> for the interaction between an exciton and optical phonons in
<> fractional-dimensional space are derived for two illustrative
<> cases of 1s-->1s and 1s-->2p exciton scattering. The improved
<> Hamiltonians incorporate any modification in the strength of
<> the exciton-optical-phonon interactions due to confinement, by
<> means of a single parameter alpha, a measure of the
<> dimensionality of the confined system. The Hamiltonians also
<> incorporate the penetration of electron and hole wave functions
<> into the barrier region, an effect which becomes increasingly
<> significant for narrow well widths. The flexibility of the
<> derived Hamiltonians are shown in the ease of systematic study
<> of exciton linewidths in GaAs/AlxGa1-xAs quantum wells. Results
<> show the high sensitivity of the excitonic linewidths to ct due
<> to interactions with short-wavelength optical phonons.
<> KP: SEMICONDUCTOR QUANTUM-WELLS, RESONANT RAMAN-SCATTERING, QUASI-
<> 2-DIMENSIONAL EXCITONS, HETEROSTRUCTURES, LINEWIDTHS, ENERGY,
<> SUPERLATTICES, MODEL
<>
<> (243) TI: Nonparabolicity effects on electron-optical-phonon scattering
<> rates in quantum wells
<> AU: Alcalde_AM, Weber_G
<> NA: UNIV ESTADUAL CAMPINAS,INST FIS,CAIXA POSTAL 6165,BR-13083970
<> CAMPINAS,SP,BRAZIL
<> UNIV SAO FRANCISCO,DEPT FIS FERAL & APLICADA,BR-13251900
<> ITATIBA,SP,BRAZIL
<> JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1997, Vol.56, No.15,
<> pp.9619-9624
<> IS: 0163-1829
<> AB: The scattering rates for intrasubband and intersubband
<> transitions due to electron-optical-phonon interaction are
<> calculated for GaAs-AlxGa1-xAs quantum wells taking into
<> account the conduction subband nonparabolicity. For the
<> description of the confined-and interface-phonon modes we use a
<> dielectric continuum model and the nonparabolic conduction-
<> subband energy is introduced as a second order expansion of
<> k(2), the square of the electron wave vector. Our results show
<> that for transitions due to the emission of confined phonons
<> the scattering rates are significantly increased, while for
<> interface phonons the scattering rates are decreased. In
<> particular, we show that for high kinetic energies electrons
<> will relax at an almost constant rates for quantum wells larger
<> than 120 Angstrom. We show that our results can be understood
<> in terms of the phonon wave vector (or Frohlich electron-phonon
<> coupling), the density of final states, and the electron-phonon
<> overlap.
<> KP: CARRIER CAPTURE PROCESSES, CONFINED PHONONS, SEMICONDUCTORS,
<> EMISSION, GAAS, HETEROSTRUCTURES, SUPERLATTICES, MODEL, TIMES,
<> SLAB
<>
<> **** End of Data ****
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