Li Yang (杨理)
Washington University in St Louis
Li Yang (杨理) received his BS (1997) and MS (2000) from the Beijing Normal University and PhD from the Georgia Institute of Technology (2006). From 2006 to 2009, he had worked as a postdoctoral fellow at the University of California, Berkeley. In 2009, he joined the faculty of the physics department of the Washington University in St Louis. He has published more than 60 peer-reviewed articles. He received the Faculty Early Career Development Award (CAREER) from the National Science Foundation in 2015. Using first-principles simulations and models, his group is working on condensed matter physics and studying fundamental electronic structures, transport and excited-state properties of reduced dimensional materials. Recently, he is particularly interested in predicting and designing novel materials with enhanced excitonic, thermoelectric, piezoelectric, and ferroelectric effects.
2017-11-06 - 2017-11-10 Office No:
Invited by Jiangping Hu (Contact: Ann 8166)
|Talk Title: First-Principles Studies of Two-Dimensional Structures
Talk Place: M-236
Talk Time: 6-Nov-2017 10:00 am
My talk will mainly cover two parts of our recent works. In the first part, I will introduce a powerful first-principles tool, the GW-Bethe Salpeter Equation (BSE) approach, which can accurately capture many-electron interactions and predict excited-state properties of solids. Particularly, the reduced dimensionality substantially reduces the screening and enhances many-electron interactions. As a result, many-electron effects dictate quasiparticle energies and optical response of two-dimensional (2D) materials. More recently, we have developed this approach with 2D plasmon included, making us to predict enhanced renormalization of quasiparticle band gap and excitons in doped 2D structures. In the second part, I will present our predictions of the unusual electronic, optical, and thermal properties of a new family of 2D materials, black phosphorus (BP). We also find that group IV-VI materials, which are isoelectronic ones of BP, may exhibit dramatically enhanced piezoelectric effects. Interestingly, these monolayer group IV monochalcogenides are essentially spontaneously polarized and hold the robust ferroelectric effect above room temperature, which has been observed in recent experiments.
|ZGC Forum "First-Principles Studies of Two-Dimensional Structures"||M-236||2017-11-06 10:00 - 11:00||The lecture will be hosted by Prof. HM Weng|
|Meeting with Prof. Xue-dong Bai||M-951||2017-11-06 11:00 - 12:00||Prof. Bai is only available on 6-Nov.|
|Meeting with Prof. Chen Shu||M-951||2017-11-06 17:00 - 17:30||My office is M-841. I'm OK with any time on 6-Nov.|
|Meeting with Prof. Duan-lu Zhou||M-951||2017-11-07 15:00 - 17:00||Prof. Zhou is also available on 8-Nov (full day)|
|Meeting with Prof. Liu Bang-gui||M-951||2017-11-08 14:00 - 14:30||I'll be around 11.6-11.8|
|Meeting with Prof. Hu Jiangping (Time to be confirmed)||M-951||2017-11-10 11:00 - 11:30||I will be back on 9-Nov, and so, can only talk to you on 10-Nov.|