建立适于描述二维MoS2体系电子输运性质的紧束缚模型

项目名称： 建立适于描述二维MoS2体系电子输运性质的紧束缚模型

项目编号： No.11474122

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 数理科学和化学

项目作者： 郑以松

作者单位： 吉林大学

项目金额： 85万元

中文摘要： 单层二硫化钼结构是继石墨烯之后新的可实验制备而且颇受关注的二维Dirac费米子材料。相比于石墨烯，该材料具有典型的半导体带隙、传导电子的自旋与谷自由度互相锁定以及圆偏振光吸收可导致电子谷极化等电子特性。基于这些电子特性，单层二硫化钼在实现某些电子器件功能方面比石墨烯更具优势。为了密切配合相关实验进展，建立可定量描述各种二硫化钼结构的电子特性，特别是电子输运特性的紧束缚模型尤为必要。 本课题拟从第一原理计算出发建立适于各种二硫化钼结构的紧束缚模型。并利用该模型研究单层和多层二硫化钼及其纳米结构的电子能谱、光电特性、电子输运性质以及某些典型的电子多体效应等。同时，从理论上预见各种实验手段对电子自旋和谷自由度的调控作用。完成本课题研究可为合理描述二维二硫化钼材料的电子性质提供新的理论框架，解释相关实验现象，进而提出基于二维二硫化钼结构实现自旋电子学或谷电子学器件功能的理论模型。

中文关键词： 二硫化钼；量子输运；紧束缚模型；电子结构；Dirac费米子材料

英文摘要： Monolayer molybdenum disulfide(MoS2), as another experimentally accessible two-dimensional(2D) Dirac fermion material just following graphene, has recently drawn much attention. In contrast to graphene, monolayer MoS2 is a semiconductor with an appropriate bandgap. In addition, electronic spin and valley degrees of freedom are locked to each other in the low-energy electronic state. And electronic valley polarization is achievable via valley-selective circular dichroism. Just based on these unique electronic properties, monolayer MoS2 is thought to be superior to graphene in realizing some device functions. Motivated by the relevant experimental progresses, it is absolutely necessary to develop a tight-binding model to describe the electronic characteristics, in particular, the electronic transport property of 2D MoS2 structures. This proposal aims to establish the tight-binding models valid to the two-dimensional MoS2. Then, by means of such a model, we study the electronic structures, optoelectronic features, electronic transport and some typical electronic many-body effects of the monolayer or few-layer MoS2 and their nanostructures. Meanwhile, we pay attention to the theoretical approaches to manipulate the electronic spin and valley degrees of freedom by the experimentally controllable measures in the 2D MoS2. Thus, the new electronic properties of the two-dimensional Dirac fermion materials can be revealed. And some promising device applications of MoS2 in the fields of spintronics and valleytronics can be theoretically suggested.

英文关键词： molybdenum disulfide;quantum transport;tight-binding model;electronic structure;Dirac fermion material