Anharmonic phonon-phonon scattering at the interface between two solids by nonequilibrium Green's function formalism
Anharmonic phonon-phonon scattering at the interface between two solids by nonequilibrium Green's function formalism
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DOI：
10.1103/physrevb.103.174306
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发表时间：
2021-05-21
影响因子：
3.7
通讯作者：
Volz, Sebastian
中科院分区：
文献类型：
--
作者：
Guo, Yangyu;Zhang, Zhongwei;Volz, Sebastian
在固体/固体界面上热声子的非弹性散射的理解和建模仍然是一个悬而未决的问题。我们提出了一个全量子理论方案，通过非平衡绿色函数（NEGF）形式主义，在界面处的非谐声子-声子散射的影响进行量化。基于实空间散射率矩阵，分解的界面光谱能量交换的本地和非本地的非谐相互作用，其中前者被证明是占主导地位的高频声子，而两者都是重要的低频声子的贡献。界面声子模的非谐衰减被揭示在桥接体模穿过界面中起着至关重要的作用。非谐性对热边界传导的整体定量贡献被认为是温和的。目前的工作促进了更深入的了解在界面处的热输运和非谐声子NEGF形式主义的直观解释。
The understanding and modeling of inelastic scattering of thermal phonons at a solid/solid interface remain an open question. We present a fully quantum theoretical scheme to quantify the effect of anharmonic phonon-phonon scattering at an interface via nonequilibrium Green's function (NEGF) formalism. Based on the real-space scattering rate matrix, a decomposition of the interfacial spectral energy exchange is made into contributions from local and nonlocal anharmonic interactions, of which the former is shown to be predominant for high-frequency phonons whereas both are important for low-frequency phonons. The anharmonic decay of interfacial phonon modes is revealed to play a crucial role in bridging the bulk modes across the interface. The overall quantitative contribution of anharmonicity to thermal boundary conductance is found to be moderate. The present work promotes a deeper understanding of heat transport at the interface and an intuitive interpretation of anharmonic phonon NEGF formalism.