Dr Paul Kinsler.
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(1) TI: OPTICAL-PHONON TUNNELING
AU: RIDLEY_BK
NA: UNIV ESSEX,DEPT PHYS,WIVENHOE PK,COLCHESTER CO4
3SQ,ESSEX,ENGLAND
JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1994, Vol.49, No.24,
pp.17253-17258
IS: 0163-1829
AB: LO phonons in polar material can tunnel resonantly through a
rigid barrier provided that they can excite an interface
polariton. A theory of phonon tunneling based on a macroscopic
continuum model is presented. The ability of LO phonons to be
transmitted is shown to be dependent upon there being
sufficient dispersion for the LO frequency band to overlap
significantly the ''classical'' dispersion of interface modes.
The interaction with electrons in the barrier is discussed. It
is also shown that interface modes appear in their own right
only in the frequency range below the LO band but above
omega(TO).
KP: GAAS-ALAS SUPERLATTICES, LATTICE-DYNAMICS, QUANTUM-WELL, MODES,
HETEROSTRUCTURES, VIBRATIONS, SYSTEMS
(2) TI: ANISOTROPY EFFECTS ON OPTICAL PHONON MODES IN GAAS slash ALAS
QUANTUM-WELLS
AU: CHAMBERLAIN_MP, TRALLEROGINER_C, CARDONA_M
NA: MAX PLANCK INST FESTKORPERFORSCH,POSTFACH 800665,D-70506
STUTTGART,GERMANY
HAVANA UNIV,DEPT THEORET PHYS,VELADO 10400,CUBA
JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1994, Vol.50, No.3,
pp.1611-1618
IS: 0163-1829
AB: Starting from a continuum theory of optical phonon modes in an
assumed isotropic GaAs slash AlAs quantum well, we have used
peturbation theory to determine the effects of anisotropy on
the mode frequencies. In particular, a [001]-grown quantum well
with modes dispersing along [010] and [110] has been
considered. We have derived analytical expressions for the
frequency corrections and illustrate the differences for modes
dispersing in these two directions.
KP: SUPERLATTICES, GAAS, DIRECTION
(3) TI: CONFINED AND INTERFACE ACOUSTIC PHONONS IN A QUANTUM-WIRE
AU: NISHIGUCHI_N
NA: HOKKAIDO UNIV,DEPT ENGN SCI,SAPPORO,HOKKAIDO 060,JAPAN
JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1994, Vol.50, No.15,
pp.10970-10980
IS: 0163-1829
AB: Confined and interface acoustic phonon modes in a cylindrical
quantum wire embedded in another material are analytically
investigated based on the elastic continuum model by means of
the potential theory. Confined acoustic phonon modes are
coupled modes of bulk-longitudinal and transverse acoustic
waves, classified into torsional, dilatational, and flexural
modes due to the rotational symmetry of the modes. Dispersions
of the confined modes have subband structures with finite
cutoff frequencies owing to quantization of wave vectors in the
lateral direction. The density of confined phonon states
becomes, as a result, a staircaselike structure. As for the
interface modes, regions of material parameters for the
possible existence of interface modes are investigated. We
found that the existence of interface modes in a quantum wire-
surrounding system becomes more sensitive to the combinations
of materials than that for a plane interface.
KP: ONE-DIMENSIONAL SEMICONDUCTOR, WELL WIRES, SCATTERING RATES, LO
PHONONS, GAAS, ELECTRONS, MOBILITY, MODES, RELAXATION,
TRANSPORT
(4) 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
(5) TI: SMITH-PURCELL EFFECT IN GAAS slash ALGAAS HETEROSTRUCTURES
AU: GORNIK_E, BOXLEITNER_W, ROSSKOPF_V, HAUSER_M, WIRNER_C,
WEIMANN_G
NA: INST FESTKORPERELEKTR,FLORAGASSE 7,A-1040 VIENNA,AUSTRIA
TECH UNIV MUNICH,WALTER SCHOTTKY INST,D-85748 GARCHING,GERMANY
JN: SUPERLATTICES AND MICROSTRUCTURES, 1994, Vol.15, No.4, pp.399-
404
IS: 0749-6036
AB: We report a new experimental technique to study the form of the
hot electron distribution function in GaAs slash AlGaAs
heterostructures. A weak periodic surface potential induces
Smith-Purcell-FIR-radiation of the electric field driven hot
electrons in the 2-dimensional electron gas directly reflecting
their velocity distribution. The FIR- radiation is detected by
a magnetic field tuned InSb-detector. In samples with very low
electron concentration and high mobility the emission spectra
show a significant shift to higher energies and develop a steep
high energy slope with increasing electric field when we use
the geometry with grating vector q directed parallel to the
electric field (q parallel to E). In the geometry q
perpendicular to E smooth decays are observed at fewer
energies. Comparison of the results with theory gives
experimental evidence of a non-equilibrium shape of the
distribution caused by the onset of LO-Phonon emission. In
addition, the hot electron mean free path of the heated
distribution is derived by investigating the experimental
emission spectra as a function of the grating period length.
The influence of a limited hot electron mean free path on the
spectral width is described in terms of a Fourier- analysis of
the interaction potential. In drift direction a mean free path
of lambda = 200 nm is obtained, whereas the mean free path is
smaller in the direction perpendicular to the drift direction.
KP: DRIFT VELOCITY, HOT-ELECTRONS
(6) TI: INTERFACE, GUIDED AND NON-LOCALIZED MODES IN SUPERLATTICES
AU: BRAZIS_R, NARKOWICZ_R, SAFONOVA_L
NA: VILNIUS SEMICOND PHYS INST,GOSTANTO 11,VILNIUS 2600,LITHUANIA
ASSOCIAT POLISH SCIENTISTS LITHUANIA,POLISH UNIV,VILNIUS
2055,LITHUANIA
JN: ACTA PHYSICA POLONICA A, 1995, Vol.87, No.2, pp.333-336
IS: 0587-4246
AB: The numerical dispersion calculations in long-period GaAs slash AlAs
superlattice were performed using a local theory with
retardation as well as an effective medium approximation. The
splitting of the dispersion branches near the transverse
optical phonon frequencies and phonon-like to photon-like modes
transition were found to depend on the superlattice spatial
period. The characteristic frequencies of bulk modes and
crossing point of dispersion branches estimated analytically
with the use of an effective medium approximation were found to
agree with the results of rigorous solution.
KP: SURFACE
(7) TI: CAPTURE OF CARRIERS INTO A GAAS slash ALGAAS QUANTUM-WELL RELEVANCE
TO LASER PERFORMANCE
AU: HAVERKORT_JEM, BLOM_PWM, VANHALL_PJ, CLAES_J, WOLTER_JH
NA: EINDHOVEN UNIV TECHNOL,COBRA INTERUNIV RES INST,DEPT PHYS,POB
513,5600 EINDHOVEN,NETHERLANDS
JN: PHYSICA STATUS SOLIDI B-BASIC RESEARCH, 1995, Vol.188, No.1,
pp.139-152
IS: 0370-1972
AB: An experimental and theoretical study of the carrier capture
time into a semiconductor quantum well is presented.
Oscillations of the phonon emission induced capture time are
experimentally observed and good agreement with theory is
found. The calculations show that not only the LO-phonon
emission induced capture time (ph-capture) oscillates as a
function of well width, but also the carrier-carrier scattering
induced capture time (c-c capture) oscillates by more than one
order of magnitude as a function of the active layer design.
Recently it has been shown that the carrier capture time is
directly related to the modulation band width in a quantum well
laser. As a result, it might be possible to tailor the
modulation band width by optimizing the capture efficiency
using a proper design of the active layer in a quantum well
laser.
KP: THRESHOLD CURRENT, TRANSPORT, BARRIER, SCATTERING, LAYERS
(8) TI: THEORY OF NONEQUILIBRIUM CARRIER THERMALIZATION LIMITED BY
PHONON-SCATTERING IN SEMICONDUCTORS
AU: KIM_CS
NA: CHONNAM NATL UNIV,DEPT PHYS,KWANGJU 500757,SOUTH KOREA
JN: JOURNAL OF THE KOREAN PHYSICAL SOCIETY, 1995, Vol.28, No.SS,
pp.S 296-S 304
IS: 0374-4884
AB: The equilibration of nonequilibrium electrons in semiconductors
is studied on time scales where the Boltzmann equation is the
founded theoretical basis. The nonequilibrium electrons are
optically injected into a sample by ultrashort laser pulses
above the band gap in experiments. The created energetic
electrons relax to equilibrium in time via interactions with
various excitations among which phonon scattering is a dominant
energy loss mechanism in pure semiconductors. We report the
results of theoretical investigations of two specially prepared
isolated systems: one is relevant to polar semiconductors such
as GaAs dominated by optical phonon scattering and the other
one has some relevance to nonpolar semiconductors like Ge
limited by acoustic phonon scattering. The relaxation of the
electron energy distribution function is investigated and, in
addition, the obtained time-dependent distribution functions
are utilized to evaluate the transient transport properties
such as hot electron temperature, decay rate of average energy,
and transient drift mobility in the presence of an external
electric field.
KP: GAAS, SPECTROSCOPY, LUMINESCENCE, RELAXATION
(9) TI: FIRST-PRINCIPLES CALCULATIONS OF THE PHONON-SPECTRUM IN
SEMICONDUCTORS
AU: LEE_IH, CHEONG_BH, CHANG_KJ
NA: KOREA ADV INST SCI & TECHNOL,DEPT PHYS,373-1 KUSUNG DONG,YUSUNG
KU,TAEJON 305701,SOUTH KOREA
JN: JOURNAL OF THE KOREAN PHYSICAL SOCIETY, 1995, Vol.28, No.SS,
pp.S 267-S 272
IS: 0374-4884
AB: We present the results of first-principles pseudopotential
calculations for the phonon spectrum of Si and GaAs within the
local-density functional approximation. From a limited set of
planar force constants obtained from the supercell approach,
the dynamical matrix is constructed and used to determine the
phonon dispersion and the phonon density of states. For GaAs,
due to the well-known long range interaction, we only calculate
the phonon spectrum along the Gamma --> X and Gamma --> L axis.
The calculated phonon frequencies are in good agreement with
experimental data. We also calculate the phonon density of
states for amorphous Si from first-principles molecular
dynamics simulations, which are considered to be more
appropriate for nonperiodic systems, and find fairly good
agreement with experiments and other calculations.
KP: ABINITIO MOLECULAR-DYNAMICS, AMORPHOUS-SILICON, FORCE-CONSTANTS,
MICROSCOPIC THEORY, LATTICE-DYNAMICS, SI, DISPERSIONS,
SIMULATIONS, GAAS
(10) TI: AB-INITIO CALCULATIONS OF PHONONS AT SEMICONDUCTOR SURFACES
AU: SCHRODER_U, FRITSCH_J, PAVONE_P
NA: UNIV REGENSBURG,INST THEORET PHYS,D-93040 REGENSBURG,GERMANY
JN: PHYSICA B, 1996, Vol.220, pp.434-435
IS: 0921-4526
AB: In the context of an ab initio linear-response approach we have
applied the density-functional theory to the investigations of
structural and dynamical properties of semiconductor surfaces.
The relaxation geometry was found by minimizing the total
energy with the help of the Hellmann-Feynman forces. We present
the full phonon dispersion of GaAs (110) and InP (110) along
high symmetry lines of the surface Brillouin zone and the bond-
stretching frequencies of these surfaces covered with one
monolayer hydrogen. All calculated frequencies compare very
well with all available experimental data from HREELS and He
atom scattering.
KP: GAAS(110)
(11) TI: STRUCTURE OF COUPLED CARRIER PLASMON-POLAR PHONON MODES 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.358, No.1-3, pp.87-91
IS: 0039-6028
AB: By combining the dielectric-response theory of a semi-infinite
electron gas with the Lorentzian oscillator model, we
investigate the structure of coupled carrier plasmon-polar
phonon modes at semiconductor surfaces, The coupling character
is 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 an on-surface component
resulting from termination of the phonon and background
polarization at the surface. The spatial structure of each mode
is visualized in contour maps of the induced charge-density
distribution. We follow the variation of the coupling character
and the spatial structure of each coupled surface mode with
change of carrier concentration through a strong-coupling
range.
KP: ENERGY-LOSS SPECTROSCOPY, SPACE-CHARGE LAYER, COLLECTIVE
EXCITATIONS, ACCUMULATION LAYERS, GAAS(110) SURFACES, INAS(110),
DEPLETION, 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
(12) TI: DIRECT MEASUREMENTS OF ENERGY RELAXATION-TIME OF ELECTRONS IN
ALGAAS slash GAAS HETEROSTRUCTURES UNDER QUASI-EQUILIBRIUM CONDITIONS
AU: VEREVKIN_AA, PTITSINA_NG, CHULCOVA_GM, GOLTSMAN_GN,
GERSHENZON_EM, YNGVESSON_KS
NA: MOSCOW STATE PEDAG UNIV,DEPT PHYS,MOSCOW 119435,RUSSIA
UNIV MASSACHUSETTS,DEPT ELECT & COMP ENGN,AMHERST,MA,01003
JN: SURFACE SCIENCE, 1996, Vol.362, No.1-3, pp.569-573
IS: 0039-6028
AB: For the first lime, results are presented of a direct
measurement of the energy relaxation time tau(epsilon) of 2D
electrons in an AlGaAs slash GaAs heterojunction at T=1 and 5-20 K. A
weak temperature dependence of tau(epsilon) for the T>4 K range
and a linear temperature dependence of the reciprocal of
tau(epsilon) for T<4K have been observed. The linear dependence
tau(epsilon)(-1)approximate to T in the Bloch-Gruneisen regime
is direct evidence of the predominance of the piezo-electric
mechanism of electron-phonon interaction in non-elastic
electron scattering processes. The values of tau(epsilon) in
this regime are in very good agreement with the results of the
Karpus theory. At higher temperatures, where the deformation-
potential scattering becomes noticeable, a substantial
disagreement between the experimental data and the theoretical
results is observed.
KP: SEMICONDUCTOR LAYERS, TRANSPORT, GAAS, HETEROJUNCTION,
TEMPERATURES, MOBILITY, GAS
WA: ALUMINUM, ARSENIC, ELECTRICAL TRANSPORT MEASUREMENTS, ENERGY
DISSIPATION, GALLIUM, GALLIUM ARSENIDE, HETEROJUNCTIONS,
PHOTOCONDUCTIVITY, SEMICONDUCTING FILMS, SEMICONDUCTOR-
SEMICONDUCTOR HETEROSTRUCTURES, SEMICONDUCTOR-SEMICONDUCTOR
INTERFACES
(13) 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 slash ALAS SUPERLATTICES, CYCLOTRON-RESONANCE, DIELECTRIC SLAB,
BOUND POLARON, CRYSTAL SLAB, SELF-ENERGY, MODES
(14) TI: Theory of localized phonons on III-V(110) surfaces
AU: Tutuncu_HM, Srivastava_GP
NA: UNIV EXETER,DEPT PHYS,EXETER EX4 4QL,DEVON,ENGLAND
JN: JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS, 1997, Vol.58, No.4,
pp.685-694
IS: 0022-3697
AB: We have calculated localized phonons on the (110) surfaces of
GaAs, GaP, InAs and InP using the adiabatic bond-charge model,
within a repeated slab scheme. Our results compare well with
available high-resolution electron-energy-loss spectroscopy
measurements and recent first principles theoretical results.
Trends in frequencies and polarisation of surface phonon modes
are examined. We find that the displacement patterns of the
zone centre modes are similar for all the considered surfaces
and that the difference in their energies can be explained in
terms of the reduced mass difference. We also present a
discussion on the trend in the location and dispersion of zone
boundary Rayleigh wave as well as the highest surface optical
frequency Fuchs-Kliewer phonon mode. (C) 1997 Elsevier Science
Limited.
KP: SEMICONDUCTOR SURFACES, DISPERSION CURVES, GAAS(110), GEOMETRY,
DYNAMICS, GAAS
WA: III-V(110), surface phonons, mass trend, Rayleigh wave, Fuchs-
Kliewer phonons, adiabatic bond-charge model
(15) TI: Polar optical modes in semiconductor nanostructures
AU: Velasco_VR, GarciaMoliner_F
NA: CSIC,INST CIENCIA MAT,E-28049 MADRID,SPAIN
UNIV JAUME I,CATEDRA CIENCIA CONTEMPORANEA,CASTELLO DE PLANA
12071,SPAIN
JN: SURFACE SCIENCE REPORTS, 1997, Vol.28, No.5-6, pp.125-176
IS: 0167-5729
DT: Review
AB: Polar optical modes play an important role in electron-phonon
processes such as scattering rates, polaron effects and
resonant Raman scattering in quantum wells and superlattices,
Because of this there has been in recent years a strong
interest in the development of a long-wave theory for optical
modes in semiconductor nanostructures. This theory would be the
equivalent of the effective mass theory for electrons. Besides
microscopic calculations it should provide a satisfactory
theoretical model to study the long-wave limit, to which most
experimental evidence is circumscribed. Important elements in
this type of theory are the inclusion of the bulk spatial
dispersion of the optical modes together with the fact that, at
an interface between two media, mechanical and electromagnetic
boundary conditions must be satisfied, In some cases, like
InAs slash GaSb and related superlattices, the details of the
interface structure are also important. We discuss here the
different approaches employed to study the long-wave limit in
these systems, including other approaches in which the envelope
function model is derived directly from microscopic lattice
dynamics.
KP: ELECTRON-PHONON INTERACTION, GAAS-ALAS SUPERLATTICES, ENERGY-
LOSS SPECTRUM, PLANAR VIBRATIONAL-MODES, RECTANGULAR QUANTUM
WIRE, RAMAN-SCATTERING, GAAS slash ALAS SUPERLATTICES, CONFINED LO,
INTERFACE MODES, RESONANT RAMAN
WA: phonons, heterostructures, quantum wells, superlattices
(16) TI: Ab initio calculation of vibrational modes in semiconductors
AU: Petzke_K, Schrepel_C, Scherz_U
NA: TECH UNIV BERLIN,INST THEORET PHYS,HARDENBERGSTR 36,D-10623
BERLIN,GERMANY
JN: ZEITSCHRIFT FUR PHYSIKALISCHE CHEMIE-INTERNATIONAL JOURNAL OF
RESEARCH IN PHYSICAL CHEMISTRY & CHEMICAL PHYSICS, 1997,
Vol.201, No.Pt1, pp.317-322
IS: 0942-9352
AB: We calculate vibrational modes in semiconductors using density-
functional theory in the local density approximation and norm-
conserving Troullier-Martins pseudopotentials. We obtain the
vibration frequencies from a direct calculation of the
dynamical matrix by using the supercell method with plane wave
expansion. In order to show the feasibility of the method we
here present the results for the phonon-dispersion curves of
GaAs, ZnSe and cubic GaN crystals, which are in very good
agreement with neutron-scattering experiments and second-order
Raman spectroscopy.
KP: ABINITIO CALCULATION, PHONON DISPERSIONS
WA: vibrational modes, phonon dispersion curves, GaAs, ZnSe, GaN
(17) TI: Continuum treatment of phonon polaritons in semiconductor
heterogeneous structures
AU: Comas_F, TralleroGiner_C, Cardona_M
NA: UNIV HAVANA,DEPT THEORET PHYS,HAVANA 10400,CUBA
MAX PLANCK INST FESTKORPERFORSCH,D-70569 STUTTGART,GERMANY
JN: PHYSICAL REVIEW B-CONDENSED MATTER, 1997, Vol.56, No.7,
pp.4115-4127
IS: 0163-1829
AB: A phenomenological approach is applied to the theory of phonon
polaritons in semiconductor heterogeneous structures, with
special emphasis on semiconductor nanostructures. Applying the
macroscopic approach to continuous media, seven coupled partial
differential equations are derived for the fundamental
quantities involved: the three components of the displacement
field u, those of the magnetic potential A, and the electric
potential phi in the Lorentz gauge. Our treatment is rather
general in its conception: no assumptions on the system
geometry and composition are made. We develop a general method
allowing us to obtain the exact analytical solutions of the
equations when the constituent materials can be assumed to be
isotropic. The matching boundary conditions at the structure
interfaces are derived from the differential equations and
interpreted in physical terms. This theory leads to a
phenomenological description of phonon polaritons valid in the
long-wavelength limit. We apply it to the case of the double
heterostructure, and calculate both the mechanical
displacements u and the potentials A, phi of normal modes in
the GaAs slash AlAs prototype system. We also discuss the dispersion
relations for these modes which are of transverse-electric and
transverse-magnetic character. A comparison is made with some
limiting cases: the unretarded case (c-->infinity) reproducing
our previous results for polar-optical phonons, and the
nondispersive case (beta(T)-->0), which leads to the Fuchs-
Kliewer slab modes.
KP: GAAS ALAS SUPERLATTICES, OPTICAL MODES, OSCILLATIONS, SYSTEMS
(18) TI: Planar vibrational modes in semiconductors: A simple model
AU: PerezAlvarez_R, TralleroGiner_C
NA: UNIV HAVANA,DEPT THEORET PHYS,HAVANA 10400,CUBA
JN: PHYSICA SCRIPTA, 1997, Vol.56, No.4, pp.407-411
IS: 0281-1847
AB: A macroscopic continuum model for optical phonon modes is
applied to obtain the planar vibrational modes of a monoatomic
layer embedded in a homogeneous material. The differences in
optical force constants and reduced masses across the atomic
plane are considered within the theory as a fundamental factor
to describe the modes localized at the interface. We have
derived analytical expressions for the phonon spectrum, as well
as for the vector displacement and electric potential as a
function of coordinates. An analysis of the infrared and Raman
activity for the obtained modes is given together with a
comparison with recent experimental data.
KP: POLAR OPTICAL OSCILLATIONS, LONG-WAVELENGTH LIMIT, RAMAN-
SCATTERING, INAS slash GASB SUPERLATTICES, INTERFACE PHONONS, GAAS,
HETEROSTRUCTURES, QUALITY, LAYERS
**** End of Data ****
Email Feedback:
Dr.Paul.Kinsler@physics.org
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