Simon Munyan

Date: June 14, 2024

Zero-field Wigner solids in ultra-thin films of Cd3As2

The quantum Wigner crystal is a many-body state where Coulombic repulsion causes
electrons to crvstallize into a solid. Experimental realization of a quantum Wigner crystal at
zero magnetic field has been a long-sought goal. In this talk, Simon will present the recent
discovery of both electron and hole Wigner solids in ultra-thin films of Cd.As, at zero
magnetic field. The Wigner solids are composed of pinned domains which produce
hysteretic switching behavior in DC transport. Landau level spectroscopy indicates that the
formation of the Wigner solid is closely connected to a topological transition as the film
thickness is reduced

Evgeny Redekop

Date: January 17, 2025

NanoSQUID-on-Tip: A Hypersensitive Tool for Exploring Topological Phases in 2D Materials

Evgeny works in Andrea Young's aroup. His area of expertise lies in nanoSQUID maanetometry with a specific application to the stud of 2D materials and heterostructures. Currentlv, his research is centered around the exploration of novel topoloaical phases intransitional metal dichalcogenide (MD) heterostructures.

Richen Xiong 

Date: June 2, 2023

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.