Excitons arising from generalized Wigner crystal states in two-dimensional moiré superlattices

Moiré superlattices of transition-metal dichalcogenides host strong Coulomb interactions within narrow electronic bands, giving rise to correlated insulating states at fractional carrier fillings, known as generalized Wigner crystals. The outstanding question naturally arises: how the excited states emerge from such correlated ground states. A microscopic description of these Wigner crystalline excitons (WCEs) is needed for the understanding of exotic excitonic phases. In this work, we develop a new computational scheme using density functional theory and GW-Bethe-Salpeter equation methods to study the excitonic properties of the moiré generalized Wigner crystals. Our study directly reveals the internal structures of WCEs and unveils the propagation of correlation effects from the ground state to excited states [1]. These results demonstrate the rich physics of moiré excitons in generalized Wigner crystals and establish a reliable first-principles framework for studying correlated excited states across moiré systems.

1.         J.-Y. You, C.-E. Hsu, Z. Zhu, B. Zhang, Z. Ye, M. H. Naik, T. Cao, H.-C. Hsueh, S. G. Louie, M. Del Ben and Z. Li, Moiré excitons in generalized Wigner crystals, arXiv:2509.08211 (2025).