R. G. Herb Condensed Matter Seminars |
Events on Tuesday, February 21st, 2023
- Interacting Opto-Moiré Quantum Matter
- Time: 10:00 am - 6:00 pm
- Place: 5310 Chamberlin
- Speaker: Xi Wang, U Washington
- Abstract: Moiré superlattices of 2D materials are an emerging platform for studying new physical
phenomena with high tunability. Strong excitonic responses in Transition Metal Dichalcogenides
(TMDs) allow optical access to the wealth of correlated physics. In this talk, I will present our
recent results about interactions between moiré excitons and charge carriers trapped in moiré
potentials. We have discovered a new interaction between exciton and charges enabled by
unusual quantum confinement in 2D moiré superlattices, which results in novel exciton many-
body ground states composed of moiré excitons and correlated electron lattices. The phase
diagram is further enriched when we investigate the magnetic interactions with optical
excitation. We have observed that the spin-spin interactions between moiré trapped holes can be
drastically tuned by optical excitation power, pointing to the excitons mediated long-range
exchange interaction between moiré trapped carriers. This discovery adds a new and dynamic
tuning knob to the rich many-body Hamiltonian of moiré quantum matter. Our work provides the
framework for understanding and engineering electronic and excitonic states in moiré quantum
matters. - Host: Victor Brar