Graduate and Postdoc Fellow Seminar: Richen Xiong

Correlated insulator of excitons in moiré Bose-Hubbard model

I got my B.S degree in Peking University and joined physics department of UCSB in 2021. Advised by Chenhao Jin, I study optical imaging and ultrafast spectroscopy in 2D materials, Here I will talk about our results on correlated excitons in WSe2/WS2 moiré superlattices. We developed a new kind of pump-probe spectroscopy and use it to reveal the bosonic correlated insulator of excitons. Upon electron doping, excitons corporate with electrons and form a mixed correlated insulator. Our results show semiconductor moirésuperlattices as an intriguing platform for studying Bose-Hubbard model and boson-fermion mixture.