介观系统中非弹性热电输运的研究

Nowadays, concepts in mesoscopic physics are commonly exploited to facilitate the development of high-performance thermoelectric materials. For example, disorders and nanostructures are introduced to manipulate electron and phonon transport in the aim of realizing higher energy efficiency. However, most of the concepts and methods are based on the theory of elastic transport. Introducing inelastic transport in mesoscopic systems as a new approach may lead to thermoelectric efficiency and output power exceeding those for elastic thermoelectric transport processes. Although this concept is at its initial stage of development, there have been considerable theoretical and experimental advancements. This research proposal is aimed at extending the concepts and theory in inelastic mesoscopic thermoelectric transport. Motivating the field with theoretical models and calculations based on realistic materials, to uncover the physics in inelastic mesoscopic thermoelectric transport and to design efficient and powerful thermoelectric devices. In addition, mesoscopic systems have strong fluctuations, which reveal abundant physics. Fluctuations in thermoelectric transport also reveal intrinsic physical properties of the system which should be studied in depth.

目前高性能热电材料的理论研究大多基于弹性输运理论，并通常借鉴介观物理中的概念，例如引入无序和纳米结构来调控电子和声子的输运从而达到更高的能量效率。然而，现有的概念和方法大多基于弹性热电输运理论。在介观系统中引入非弹性热电输运作为一种新的方法，有望实现超越弹性热电输运过程的最佳能量效率和输出功率。虽然该方法的提出和发展已经取得了一定的理论和实验成果，但整体尚处于初始发展阶段。本项目旨在进一步推广非弹性介观热电输运研究的概念和理论，通过探索模型系统和计算真实材料从而发现非弹性热电输运的实际物理规律，并设计具有高能量效率和功率的物理器件。另外，介观系统的输运涨落能够发映出丰富的物理信息，我们将研究非弹性介观热电输运的涨落性质，探索其中的本征物理性质。

为进一步提升热电转换的能量效率和输出功率，本项目研究了介观系统非弹性热电输运中的一系列重要物理问题，探索了可能的物理机制、材料系统、器件功能。本项目重点研究如下三个方面的科学问题：1.非弹性热电输运的微观机理，2.非弹性热电输运的基本物理特性，3.时间反演对称破缺系统的热电输运研究。各项研究目标按计划执行得很好。虽然研究生招生过程中有过一些曲折，但截止目前为止，各项研究进展顺利，取得了不错的研究成果。