报告人：香港大学物理系姚望教授
时间 ：12月12日（周一）上午9:30
地点：大学城理六栋 220
题目：Valley-spintronics in 2D semiconductors
姚望教授简介：
       香港大学物理系教授，他于2001年从北京大学获得学士学位,2006年于美国加州大学（UCSD）获得博士学位,2006-2008年在德州大学奥斯丁分校从事博士后研究。2008年加盟香港大学物理系。在二维物理体系的物理性质以及量子信息领域做出过重大成果。目前发表论文70余篇，其中 Science、Nature、Nature子刊论文22篇，Phys. Rev. Lett. 18篇；这些论文每年被SCI发表论文引用约2000次，有19篇论文SCI引用超过了100次。曾获得华人物理与天文协会亚洲杰出研究奖，香港裘槎基金会优秀科研者奖和香港大学突出贡献奖等。

报告内容摘要： 

    The Bloch bands in many crystals have a degenerate set of energy extrema in momentum space known as valleys. For bandedge carriers, the valley index becomes a discrete degree of freedom in addition to spin, which can be utilized as information carrier. In monolayer transition metal dichalcogenides (TMDs), a newly emerged class of semiconductors in the 2D limit, I will show that electrons and holes have a time reversal pair of valleys that are associated with varieties of novel phenomena. These include the valley optical transition selection rules, valley Hall effects, and valley magnetic moment, which are analog of the spin phenomena in conventional semiconductors, enabling the use of both valley and spin with versatile controllability for future electronics. Stacking 2D TMDs into van der Waals (vdW) heterostructures further provides a powerful approach towards designer condensed matter systems that can extend the already exotic properties of the 2D building blocks. I will show that a vdW heterobilayer of TMDs can realize programmable and electrically switchable lateral superstructures of topological insulators, which can have profound impact on quantum electronics and spintronics.