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  • 1
    Electronic Resource
    Electronic Resource
    Effects of interface phonon scattering in multiheterointerface structures (1992)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 72 (1992), S. 2282-2287 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: 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 A(ring), this simplified description can be applied to multiheterointerface structures in general with reasonable accuracy.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.351569
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  • 2
    Electronic Resource
    Electronic Resource
    Radiation of acoustic phonons from quantum wires (1995)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 77 (1995), S. 5095-5097 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We have investigated by the Monte Carlo technique the radiation of ballistic acoustic phonons from quasi-one-dimensional electron gas in quantum wires. At low temperatures and over a wide range of electric fields, all excess heat in quantum wires is dissipated by means of acoustic phonons. Due to the uncertainty of momentum conservation during electron–acoustic-phonon scattering, electrons emit acoustic phonons with large transverse momentum components. Consequently, in this transport regime quantum wires radiate fluxes of nonequilibrium acoustic phonons into surrounding material. Nonequilibrium acoustic phonons can propagate ballistically over macroscopic distances. Ballistic fluxes of nonequilibrium acoustic phonons have been previously detected experimentally in quantum well structures. We have calculated the angular and energy spectrum of nonequilibrium acoustic phonons radiated from quantum wires. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.359318
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  • 3
    Electronic Resource
    Electronic Resource
    Quantized acoustic phonon modes in quantum wires and quantum dots (1994)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 76 (1994), S. 4670-4675 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Acoustic phonon modes in isotropic cubic media are derived for a number of quantum-wire and quantum-dot geometries of significant interest in nanoelectronics and optoelectronics. In each case, the mode amplitude is determined by requiring that the mode energy be given by that of the properly quantized phonon. For the case of cylindrical quantum wires and quantum dots with rectangular faces, the Hamiltonians for the deformation potential interactions are derived. These quantized acoustic modes and the associated deformation potential Hamiltonians provide a basis for modeling carrier-acoustic-phonon interactions in a variety of mesoscopic devices. Our new results supplement previous treatments of related piezoelectric effects in cylindrical quantum wires.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.357305
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  • 4
    Electronic Resource
    Electronic Resource
    Hot-electron relaxation dynamics in quantum wires (1994)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 76 (1994), S. 1021-1028 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: 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 105 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(approximately-greater-than)0.5 ps the hot phonon thermalization time defines the characteristic electron cooling time.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.357889
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  • 5
    Electronic Resource
    Electronic Resource
    Transitions between Γ and X states of short-period superlattices driven by antisymmetric interface phonons (1994)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 75 (1994), S. 1977-1981 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Relative transition probability amplitudes for antisymmetric-interface-phonon-assisted Γ-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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.356321
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  • 6
    Electronic Resource
    Electronic Resource
    Interface-phonon-assisted Γ–X transitions in short-period superlattices (1993)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 73 (1993), S. 1693-1701 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: 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 Γ–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 Γ–X transitions are expected and to estimate relative transition probability amplitudes for interface-phonon-assisted Γ–X transitions in selected short-period superlattices.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.354060
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  • 7
    Electronic Resource
    Electronic Resource
    Phonon enhanced inverse population in asymmetric double quantum wells (1999)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 75 (1999), S. 3258-3260 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Interwell optical-phonon-assisted transitions are studied in an asymmetric double-quantum-well heterostructure comprising one narrow and one wide coupled quantum wells (QWs). We show that the depopulation rate of the lower subband states in the narrow QW can be significantly enhanced thus facilitating the intersubband inverse population, if the depopulated subband is aligned with the second subband of the wider QW, while the energy separation from the first subband is tuned to the highest energy optical-phonon mode. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.125317
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  • 8
    Electronic Resource
    Electronic Resource
    Comment on "Energy level schemes for far-infrared quantum well lasers" [Appl. Phys. Lett. 73, 300 (1998)] (1999)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 74 (1999), S. 2555-2555 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.123898
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  • 9
    Electronic Resource
    Electronic Resource
    Electron interaction with confined acoustic phonons in cylindrical quantum wires via deformation potential (1996)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 80 (1996), S. 2815-2822 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: 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. © 1996 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.363199
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  • 10
    Electronic Resource
    Electronic Resource
    Interface-phonon-assisted transitions in quantum-well lasers (1996)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 80 (1996), S. 6864-6867 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Interface-phonon-assisted transitions are 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. © 1996 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.363754
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