典型二维六角晶格材料中谷相关电子输运特性的理论研究

项目名称： 典型二维六角晶格材料中谷相关电子输运特性的理论研究

项目编号： No.11504240

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 数理科学和化学

项目作者： 许富明

作者单位： 深圳大学

项目金额： 20万元

中文摘要： 谷电子学是当前凝聚态物理和材料物理领域的研究热点之一，其目标是调控电子的谷自由度来传递信息，并构建高效率、低能耗的谷电子学器件。谷是材料中除电荷及自旋外新的可操控自由度，最早发现于二维六角晶格材料。石墨烯和过渡金属二硫化物是典型的二维六角晶格材料，对其谷输运特性的研究在谷电子学的基础理论和实际应用方面均有重要意义。本项目拟采用非平衡格林函数方法，结合第一性原理计算、紧束缚模型及低能有效模型等，对典型二维六角晶格材料石墨烯和过渡金属二硫化物的谷相关电子输运特性进行理论和数值研究。主要研究内容包括：纯谷流的电学产生和量子谷源的架构；应力对单层过渡金属二硫化物谷输运特性的影响；量子谷霍尔效应及其在无序下的统计行为描述等。这些研究将有助于提升对典型二维六角晶格材料谷相关输运特性的理解，为谷电子学器件设计提供理论参考，从而推动谷电子学的发展。

中文关键词： 量子输运性质；谷电子学；纳米石墨带；过渡金属二硫化物；非平衡格林函数

英文摘要： Valleytronics has attracted intensive research interests from both condensed matter physics and material science fields. It aims to control and manipulate the valley degree of freedom of electron to carry information, and construct high-efficiency, low-cost valleytronic devices. In addition to charge and spin, valley is the new degree of freedom of electron and first discovered in 2-dimensional (2D) honeycomb-lattice materials. Graphene and transition metal dichalcogenides (TMDs) are typical 2D honeycomb-lattice materials. Study on the valley-related transport properties of these materials is of both fundamental and applicable importance. In this project, we will theoretically investigate the valley-related electronic transport characteristics of typical 2D honeycomb-lattice materials: graphene and TMDs. The adopted methodology is non-equilibrium Green’s function combing first-principle calculation, tight-binding model, and k-p model, etc. Our investigation will focus on the following subjects: the electric generation of pure valley current and setup of quantum valley source; strain effect on the valley transport properties of monolayer TMDs; quantum valley Hall effect and its statistical behavior in the presence of disorder, etc. We hope that the outcome of these investigations would promote the comprehension on the valley-related transport properties of typical 2D honeycomb-lattice materials, and provide certain theoretical reference for the design of valleytronic devices.

英文关键词： Quantum transport properties;Valleytronics;Graphene nanoribbon;Transition metal dichalcogenides;Non-equilibrium Green's function