报告题目：Dynamics of Many Moire Excitons

报 告 人：Dante M. Kennes，RWTH Aachen University

内容摘要：Moiré superlattices provide a versatile platform for exploring nonequilibrium quantum dynamics of strongly interacting excitons. In this talk, I will discuss real-space and real-time imaging of many-exciton states in WSe₂/WS₂ moiré heterobilayers using time- and energy-resolved photoluminescence and ultrafast reflectance microscopy. At commensurate exciton filling, long-range dipolar repulsion produces an exciton Mott insulator whose expansion remains frozen for more than 70 ns; a counterintuitive manifestation of interaction-stabilized many-body behavior in a dissipative solid-state system. Introducing correlated electrons qualitatively transforms these dynamics: exciton–electron and exciton–exciton repulsion promotes excitons into a more dispersive moiré band, producing energy-selective ballistic expansion that is enhanced at fractional electron fillings supporting generalized Wigner-crystal order. As the exciton density decays, this ballistic flow gives way to a mixed electron–exciton Mott state. Together, these results demonstrate tunable transitions between arrested insulating behavior and collective fluid-like motion, establishing moiré materials as a platform for nonequilibrium Bose–Fermi quantum matter.

报告人简介：Dante M. Kennes is a professor at the RWTH Aachen University and visiting scientist at the Max Planck Institute for the Structure and Dynamics of Matter. His research focus lies on the theoretical study of ultrafast quantum materials design, non-equilibrium quantum many-body dynamics, and twisted van der Waals heterostructures. He uses renormalization group- or tensor network-based methods applicable to the equilibrium as well as out-of-equilibrium realm of strongly correlated systems. His research aims to realize quantum materials with specific tailored properties enabling novel quantum functionalities.