منابع مشابه
Intrinsic to extrinsic phonon lifetime transition in a GaAs-AlAs superlattice.
We have measured the lifetimes of two zone-center longitudinal acoustic phonon modes, at 320 and 640 GHz, in a 14 nm GaAs/2 nm AlAs superlattice structure. By comparing measurements at 296 and 79 K we separate the intrinsic contribution to phonon lifetime determined by phonon-phonon scattering from the extrinsic contribution due to defects and interface roughness. At 296 K, the 320 GHz phonon l...
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Longitudinal optical phonons have been used to interpret the electronic energy relaxation in quantum dots and at the same time they served as a reservoir, with which the electronic subsystem is in contact. Such a phonon subsystem is expected to be passive, namely, in a long-time limit the whole system should be able to achieve such a stationary state, in which statistical distributions of both ...
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Ultrafast spectroscopy gives insight into the relaxation and dephasing of electrons during the first femtoseconds after an optical excitation. A theoretical description of this early-time regime requires a proper treatment of retardation effects for the different scattering processes. The scattering of electrons by optical phonons is investigated within the S-matrix formalism. This perturbative...
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Femtosecond pulses are used to excite A1g optical phonons in Bi2Te3, Sb2Te3, and Bi2Te3 /Sb2Te3 superlattice. Time-resolved reflectivity measurements show both the low-frequency and high-frequency components of A1g phonon modes. By comparing the phonon lifetime, it is found that the scattering rate inverse of lifetime in superlattice is significantly higher than those in Bi2Te3 and Sb2Te3. This...
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1 By means of a microscopic valence force field model, a series of novel microscopic interface phonon modes are identified in shell quantum dots (SQDs) composed of a GaAs quantum dot of nanoscale embedded in an AlAs shell of a few atomic layers in thickness. In SQDs with such thin shells, the basic principle of the continuum dielectric model and the macroscopic dielectric function are not valid...
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ژورنال
عنوان ژورنال: Physical Review Letters
سال: 2002
ISSN: 0031-9007,1079-7114
DOI: 10.1103/physrevlett.88.215502