单层二硫化钼半导体材料中电子自旋性质的研究

项目名称： 单层二硫化钼半导体材料中电子自旋性质的研究

项目编号： No.11204184

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 物理学I

项目作者： 戴俊峰

作者单位： 南方科技大学

项目金额： 25万元

中文摘要： 谷电子学是通过除了电荷和自旋以外，不等价的能谷自由度来操控电子设备的一门学科。近年来国际上开展了对单层二硫化钼半导体能谷性质的研究，由于此材料中存在着很强的自旋轨道耦合效应和空间结构反演不对称性，理论表明在这种二维多能谷体系中可以同时操控电子自旋和能谷，认为它是很好的谷电子和自旋电子器件材料。然而，目前未有单层二硫化钼材料中关于电子或空穴自旋性质实验方面的报道。本项目利用光自旋注入和铁磁自旋探测器技术开展低温下单层二硫化钼半导体中电子或空穴的自旋极化强度以及自旋霍尔效应方面的研究。弄清单层二硫化钼材料中自旋极化方向与光偏振性的关系，影响自旋极化强度的因素以及铁磁自旋探测器的探测效率的问题，对此材料在纳米电子器件的应用前景作出评估。本课题对单层二硫化钼材料在半导体自旋电子器件和谷电子器件的发展具有重要的科学意义和实际价值。

中文关键词： 能谷；自旋能谷耦合；能谷相干性；能谷偏振度；过渡金属硫化物

英文摘要： A trend for future electronics is to utilize the internal degrees of freedom of electron for information storage and processing. The independent and degenerate valleys of energy bands constitute another discrete degree of freedom for low-energy electrons. This has led to the emergence of valleytronics, which uses the valley index to control an electronic device in addition to charge and spin. Recently, lots of theorical and experimental works on the valley properties of MoS2 monolayer have been reported. In MoS2 monolayer, the inversion symmetry breaking together with spin-orbit coupling leads to coupled spin and valley physics, making possible manipulation of spin and valley in these materials. So the MoS2 monolayer semiconductor is a potential candidate in the valley and spin electronic devices. However, there are no relevant experimental reports on spintronics research on MoS2 monolayers. In this proposal, we plan to untilize optical method to generate spin-polarized electrons and holes, while use ferromagnetic spin detector to measure the intensity of spin-polarization and the spin Hall effect. Our goal is to understand the basic physics of optical spin injection and factors influencing the spin polarization, and explore its application in nano-electronic devices. This project will be of great value to the d

英文关键词： valley；spin-valley coupling；valley coherent；valley polarization；TMDCs