Competing Generalized Wigner Crystal States in Moiré Heterostructures
ORAL
Abstract
Moiré systems have recently become a powerful platform for studying strongly correlated electronic states such as Mott insulators, generalized Wigner crystals (GWCs), and liquid crystals. In particular, the class of transition metal dichalcogenide (TMD) moiré heterostructures harbor a rich phase diagram of such states as a function of the filling factor while allowing for versatile laboratory control of physical parameters. Here, we present a comprehensive study of GWCs across various filling factors employing Hartree-Fock theory and explicitly correlated wave function approaches. While we find broad agreement with the behavior observed in experiments and classical Monte Carlo simulations, we highlight the fact that the Hartree-Fock energy landscape appears to be remarkably complex, exhibiting several competing states--both ordered and disordered--separated by energies of a fraction of ∼1 meV/hole. We demonstrate that these states are metastable by performing a stability analysis at the Hartree-Fock level. Correlated wave function methods furthermore reveal small correlation energies that are nevertheless large enough to tip the balance of state ordering found within Hartree-Fock theory.
*We acknowledge funding support from NSF CHE–2245592. Computations in this paper were primarily executed on the Ginsburg High Performance Computing Cluster at Columbia University. Some calculations were run on the FASRC Cannon cluster supported by the FAS Division of Science Research Computing Group at Harvard University. This work also used Bridges-2 Regular Memory (RM) nodes at the Pittsburgh Supercomputing Center and the Expanse cluster at the San Diego Supercomputer Center through allocation CHE220021 from the Advanced Cyberinfrastructure Coordination Ecosystem: Services & Support (ACCESS) program, which is supported by National Science Foundation grants #2138259, #2138286, #2138307, #2137603, and #2138296.
