报告人：Prof. Dr. Di Xiao

主持人：孙 政  研究员

时  间：2021年10月12日（周二）上午10：00-12：00

地  点：光学大楼B325，zoom会议id：6108034229，密码：111111

报告人简介：

Di Xiao obtained his Bachelor degree in physics from Peking University and PhD from the University of Texas at Austin.  After a four-year stint at Oak Ridge National Laboratory, he moved to Carnegie Mellon University in 2012.  He joined the University of Washington in 2021, and holds professor position in both Department of Physics and Department of Materials Science & Engineering.  Xiao is an expert in Berry phase effect, and pioneered the field of valleytronics.  He was named a Cottrell Scholar by Research Corporation for Science Advancement in 2016, Simons Fellows in Theoretical Physics in 2019, and has been a Thomson-Reuters Highly Cited Researcher since 2017.

报告内容：

Recent years have seen a surge of interest in twisted van der Waals heterostructures consisting of atomically thin crystal layers. From a structural point of view, twisted layers are interesting because not only are they chiral, but their chirality can be readily controlled by varying the twisting angle. For example, bilayers with opposite twisting angles are mirror images of each other; therefore, they possess opposite chirality. This structural flexibility makes twisted van der Waals heterostructures a versatile platform for investigating chirality-dependent phenomena.  In this talk, I will discuss two phenomena related to the chirality of twisted bilayers, namely, chiral charge pumping and layer circular photogalvanic effect.  The former relates mechanical motion to electricity, while the latter could be useful for frequency-sensitive, circularly polarized light detection, particularly in the infrared range.