Quantum mechanical analyses of nanoscale phonon transport

纳米级声子输运的量子力学分析

基本信息

批准号：
19F19353
负责人：
野村政宏
金额：
$ 1.02万
依托单位：
The University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for JSPS Fellows
财政年份：
2019
资助国家：
日本
起止时间：
2019-11-08 至 2022-03-31
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-19F19353/
关键词：
phonon phonon hydrodynamics quantum heat transport phonon NEGF formalism recursive algorithm phonon vortex Anharmonic phonon NEGF Fourier’s representation MPI parallelization heat transport

项目摘要

The research achievements under the support of JSPS fellowship mainly include three aspects:(1) We develop the three-dimensional anharmonic phonon non-equilibrium Green’s function formalism, and a parallelized computational framework for large-scale quantum heat transport simulation. With the new methodology, the open question of how anharmonic phonon-phonon scattering plays the role in heat transport at solid-solid interface is studied with a local spectral energy exchange decomposition scheme. Also we present a novel path to demonstrate phonon localization in graded superlattices and a thermal conductivity minimum phenomenon in the quantum coherent regime.(2) We develop a mesoscopic simulation framework based on the phonon Boltzmann equation under Callaway’s dual relaxation model with fully ab initio input of phonon properties for both isotropic and anisotropic material systems. With the new method, we investigate the size effect of phonon hydrodynamics in graphitic nano- and micro-structures, and promote the experimental observation of phonon Poiseuille flow in micro-meter-scale isotopically purified graphite ribbon.(3) We develop a coupled model for heat transport along polar dielectric nanostructures via phonons and surface phonon polaritons. A universal quantum of two-dimensional heat transport in ultrathin polar films is derived for surface phonon polaritons. The non-linear temperature profile due to the coupled dynamics is also demonstrated.

JSPS奖学金支持下的研究成果主要包括三个方面：（1）开发了三维非谐声子非平衡格林函数形式，以及采用新方法的大规模量子热传输模拟的并行计算框架。，通过局部光谱能量交换分解方案研究了非谐波声子-声子散射如何在固-固界面热传输中发挥作用的悬而未决的问题，我们还提出了一种证明声子的新途径。梯度超晶格中的局域化和量子相干态中的热导率最小现象。(2) 我们开发了一种基于卡拉威双弛豫模型下的声子玻尔兹曼方程的介观模拟框架，完全从头开始输入各向同性和各向异性材料的声子特性通过新方法，我们研究了石墨纳米和微米结构中声子流体动力学的尺寸效应，并促进了声子泊肃叶的实验观测。 (3) 我们开发了一种通过声子和表面声子极化子沿极性介电纳米结构热传输的耦合模型，推导了超薄极性薄膜中二维热传输的通用量子。还演示了由于耦合动力学而产生的非线性温度分布。