Dr Paul Kinsler. [Acknowledgements & Feedback]
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From firstname.lastname@example.org Thu Nov 20 12:59 GMT 1997 Received: from mps2.leeds.ac.uk (mps2 [220.127.116.11]) by sun.leeds.ac.uk (8.8.5 slash 8.8.5) with ESMTP id MAA28589 for
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Database: Science Citation Index (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 -grown quantum well with modes dispersing along  and  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 ****
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