量子结构中弹性-扩散混合热输运理论研究

Aiming at the thermal quantum devices with important applying perspective and theoretical research value, this project is going to be in deep research on the thermal-transport property of quantum structures by calculational stimulation and theoretical analysis. It is going to clarify the relationship between the thermal-transport property and external configuration, and also the relationship between the thermal-transport property and the inner-tiny structure. We also plan to analyse the influence on the thermal-transport property by the phonon-phonon coupling, investigate deeply the thermal-transport essence in atom-molecule scale, and clarify in-between ballistic-diffusive thermal transport theory between the ballistic thermal transport at very low temperatures and diffusive thermal transport at much high temperatures. On the basis of these results, we plan to establish a sort of thermal transport theoretical model which can efficaciously differentiate the ballistic thermal transport and diffusive thermal transport in the mixed ballistic-diffusive thermal transport scope, design a set of modulational program to match the new thermal transport theoretical model, and put up a new modulational platform for designing thermal quantum devices. Also, in this project, the quantum devices with extraordinary thermal-transport function are going to be designed out with good explanation by the new thermal transport theory .

本项目针对具有重要应用前景和理论研究价值的热量子器件，通过计算模拟与理论分析，对其热输运性质展开深入研究。阐明量子体系的热输运性质与其外部构形、内部微结构的关系，分析声-声耦合对热输运的影响，从分子、原子尺度范围深入调查其热输运本质，阐明从低温条件下的弹性热输运向高温条件下的扩散热输过度的中间态弹性-扩散热输运机理，建立在弹性-扩散混合热输运范围内能有效区分弹性热输运与扩散热输运的量子热输运理论模型，并编写一套与新的理论模型相匹配的模拟程序，为热量子器件的设计构建新的模拟平台，设计具有特异热输运功能的量子器件。

本项目针对具有重要应用前景和理论研究价值的热量子器件，运用量子输运理论以及非均衡格林函数、弹性波连续模型等方法，系统地研究了量子体系的热输运性质与其外部构形、内部微结构以及应变的关系，揭示了声-声耦合对热输运的影响，获得了一些具有重要科学意义的成果，主要有：（1）建立了处理量子结构中弹性-扩散混合热输运理论模型，系统研究了弹性、扩散混合热输运中弹性热输运与扩散热输运对总的热输运的不同贡献；（2）通过对量子结构实施外部结构设计、构筑空穴和量子点、压力形变等分子工程，系统地研究了热输运性质与其外部构形、内部微结构以及应变的关系，从分子、原子尺度范围深入调查其热输运本质，提出了调控热量子器件热输运性能的方法和措施；（3）对比研究了不用声学模的热输运性质，揭示了不同声学模的热输运本质。（4）对比研究了不同低维材料的热输运性质，揭示了新型纳米材料中特异的热输运本质。