Thermal conductivity minimum of graded superlattices due to phonon localization
Abstract
The Anderson localization of thermal phonons has been shown only in few nano-structures with strong random disorder by the exponential decay of transmission to zero and a thermal conductivity maximum when increasing system length. In this work, we present a path to demonstrate the phonon localization with distinctive features in graded superlattices with short-range order and long-range disorder. A thermal conductivity minimum with system length appears due to the exponential decay of transmission to a non-zero constant, which is a feature of partial phonon localization caused by the moderate disorder. We provide clear evidence of localization through the combined analysis of the participation ratio, transmission, and real-space phonon number density distribution based on our quantum transport simulation. The present work would promote heat conduction engineering by localization via the wave nature of phonons.
Keywords
Cite
@article{arxiv.2105.01832,
title = {Thermal conductivity minimum of graded superlattices due to phonon localization},
author = {Yangyu Guo and Marc Bescond and Zhongwei Zhang and Shiyun Xiong and Kazuhiko Hirakawa and Masahiro Nomura and Sebastian Volz},
journal= {arXiv preprint arXiv:2105.01832},
year = {2021}
}