时间：2021年5月13日（周四）下午2:00-3:30

Time：13 May, Thursday 2021, 2:00-3:30 PM

地点：西湖大学云栖校区2号楼611室

Venue：Room 611, 6F, Building 2, Yunqi Campus

主持人：西湖大学工学院PI 李文彬

Host：Dr. Wenbin Li, PI of School of Engineering, Westlake University

主讲嘉宾/Speaker：

周健教授，西安交通大学

Prof. Jian Zhou，Xi’an Jiaotong University

主讲人简介/Biography:

Jian Zhou received his BSc (2008) and PhD (2013) from Peking University. After appointments as Postdoc Associate at Virginia Commonwealth University and Massachusetts Institute of Technology, he joined Xi’an Jiaotong University in 2018, supported by National Young Talent Program. Prof. Zhou has over 80 peer reviewed publications, including PNAS, PRL, JACS, Nano Lett., Nat. Commun., Angew. Chem., and etc. He has over 4,000 total citations and an h-index of 25, and was selected as “Highly Cited Chinese Researchers in 2020 (MSE)”. His research interest lies in theoretical and computational studies of low-dimensional quantum materials, with the most recent focus on nonlinear optical responses on topological or ferroic materials.

讲座摘要/Abstract:

Two-dimensional materials have shown tremendous interesting features with large surface area to volume ratio. Hence, they are optically addressable and accessible. In this talk, I will discuss some recent theoretical predictions, focusing on 2D material’s optical nonlinear responses, including their geometric phase transition and electronic responses. One famous 2D material example is monolayer transition metal dichalcogenide which exists in both 2H and 1T′ phases. Non-contacting optical readout/write with focused laser would be preferable in many circumstances. We use first-principles density functional theory calculations to theoretically and computationally illustrate an optomechanical strategy to inducing geometric phase transitions, which uses a linearly polarized laser with selected frequency. I will discuss a few examples of such ultrafast diffusionless martensitic phase transition in various materials, focusing on terahertz frequency regime, which holds the essence of next generation communication technology. We predict that topological contrasting 2H and 1T’ phases have big optical responses, hence, photons would apply different work done into the system. We then suggest that THz optics irradiation could trigger 2H → 1T’ phase transition thermodynamically. This prediction agrees well with recent experimental observations (arXiv:1910.13609).

讲座联系人/Contact：

工学院办公室

戴老师 daixueping@westlake.edu.cn