报告题目 | Magneto-Optical Effects in Dirac Materials: Spin Noise and Nonlinear Faraday Effect |
报告人 | Dr. Wang-Kong Tse |
报告人单位 | Department of Physics and Astronomy.University of Alabama |
报告时间 | 2016-05-26 |
报告地点 | 合肥微尺度物质科学国家实验室九楼会议室(9004) |
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(ICQD) |
报告介绍 | Abstract:
I will discuss two examples of magneto-optical transport properties in gapped Dirac materials, focusing on 2D transition-metal dichalcogenides (TMD) and topological insulators (TI). First we will talk about the use of Faraday effect to measure the intrinsic spin fluctuations and how this facilitates the extraction of spin relaxation time in 2D TMD. It is shown that spin noise measurement provides a non-invasive method to probe the spin and valley dynamics and relaxation of 2D TMD. Secondly, we will discuss the effects of coherent excitation on TI by a strong electromagnetic field under time-reversal symmetry breaking. A signature of optical Stark effect is found to be present in the resulting nonlinear Faraday and Kerr rotations caused by conduction-valence band mixing by the optical dipole matrix element. These two examples illustrate that magneto-optics provides a useful alternative to studying spin relaxation and coherent optical properties traditionally studied using pump-probe techniques.
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