| 报告题目 | Spin and valley physics in 2D transition metal dichalcogenides |
| 报告人 | 姚望 教授 |
| 报告人单位 | Department of Physics, The University of Hong Kong |
| 报告时间 | 2015-05-20 |
| 报告地点 | 合肥微尺度物质科学国家实验室（9004室） |
| 主办单位 | 合肥微尺度物质科学国家实验室、国际功能材料量子设计中心 |
| 报告介绍 | 报告摘要：
The Bloch bands in many crystals have a degenerate set of energy extrema in momentum space known as valleys. For band-edge carriers, the valley index becomes a discrete degree of freedom in addition to spin. In this talk, I will show that in monolayer transition metal dichalcogenides, the pair of valleys which are time-reversal of each other are distinguishable by their opposite values of magnetic moment, Berry curvature, and circularly-polarized optical transition selection rule. This allows the use of valley pseudospin as information carrier for valley based electronics. I will discuss mechanisms to generate and control the spin and valley pseudospin currents, which are at the heart of spin and valley based electronics. These include: (I) the valley and spin Hall current arising from the Berry curvatures; and (II) the nonlinear valley and spin currents arising from Fermi pocket anisotropy. I will also discuss the valley Hall effect of charged excitons in monolayer TMDs, which arises from the exchange interaction between the electron and hole constituents of the exciton.
报告人简介： |
