In a strongly correlated electronic system, Coulomb interactions among electrons dominate over kinetic energy. Recently, two-dimensional (2D) moiré superlattices of van der Waals materials have emerged as a promising platform to study correlated physics and exotic quantum phases in 2D. In transition metal dichalcogenides (TMDCs) based moiré superlattices, the combination of large effective mass and strong moiré coupling renders the easier formation of flat bands and stronger electronic correlation, compared with graphene moiré superlattices. Meanwhile, the strong Coulomb interaction in 2D also leads to tightly bound excitons with large binding energy in TMDCs. In this talk, we will discuss how to use optical spectroscopy to investigate excitonic physics and strongly correlated phenomena in TMDC moiré superlattice, as well as strong interactions between excitons and correlated electrons.
 

Sufei Shi is currently an Associate Professor in the Chemical and Biological Engineering Department at Rensselaer Polytechnic Institute. He obtained B.S. in Physics from Nanjing University and M.S. in Physics from Brown University. He obtained his Ph. D in Physics from Cornell University in 2012, and he did his postdoc work at UC Berkeley from 2011 to 2015. He was awarded ACS Petroleum Research Fund Doctoral New Investigator award in 2018 and the NSF Career award in 2020.

Please contact phweb@ust.hk should you have questions about the talk.