PHONON-TRANSMISSION RATE, FLUCTUATIONS, AND LOCALIZATION IN RANDOM SEMICONDUCTOR SUPERLATTICES - GREENS-FUNCTION APPROACH

Article

关键词: ONE-DIMENSIONAL METAL;    RESONANT TRANSMISSION;    3RD SOUND;    CONDUCTIVITY;    SYSTEMS;    WAVES;   

DOI  :  10.1103/PhysRevB.48.2515

来源: SCIE

【 摘 要 】

We analytically study phonon transmission and localization in random superlattices by using a Green's-function approach. We derive expressions for the average transmission rate and localization length, or Lyapunov exponent, in terms of the superlattice-structure factor. This is done by considering the backscattering of phonons, due to the complex mass-density fluctuations, which incorporates all of the forward-scattering processes. These analytical results are applied to two types of random superlattices and compared with numerical simulations based on the transfer-matrix method. Our analytical results show excellent agreement with the numerical data. A universal relation for the transmission fluctuations versus the average transmission is derived explicitly, and independently confirmed by numerical simulations. The transient of the distribution of transmission to the log-normal distribution for the localized phonons is also studied.

【 授权许可】

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