报告摘要:

Low-dimensional structures have attracted significant interests because of their unique electrical and optical properties. In this talk, I will give a brief review about our first-principles simulations on the electronic structure and optical response of a few typical reduced dimensional structures, from one-dimensional nanowires and nanoribbons to two-dimensional graphene and fluorinated graphene. Beyond the usual density functional theory, an ab-initio approach based on the many-body perturbation theory is introduced to calculate the quasiparticle energy and optical absorption spectra of solids. I will also show how this state-of-art calculation explains available experimental measurements of nanostructures and, more importantly, predicts novel features of new materials in a quantitative way.

About the speaker

Li Yang obtained his Bachelor and Master degrees in physics from Beijing Normal University (1997, 2000) and PhD from Georgia Institute of Technology (2006). He received a postdoctoral fellow from the University of California at Berkeley and Berkeley National Laboratory (2006 to 2009). Now he works as an assistant professor in the Washington University in St Louis. His research interests are mainly about electronic excited states in nanostructures and their interfaces.