Competing Generalized Wigner Crystal States in Moir\'e Heterostructures

TL;DR

This paper investigates generalized Wigner crystal states in moiré heterostructures using advanced computational methods, revealing complex energy landscapes with many competing states and the influence of correlations on state stability.

Contribution

It provides a comprehensive analysis of Wigner crystal states across various fillings, combining Hartree-Fock and correlated wave function approaches to identify metastable states and the effects of correlations.

Findings

Hartree-Fock energy landscape is highly complex with many competing states.

Correlated wave functions show small but significant correlation energies.

Metastable states are identified through stability analysis.

Abstract

We present a comprehensive study of generalized Wigner crystals across various filling factors for system sizes up to 162 holes 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 many competing states, both ordered and disordered, separated by energies of a fraction of $\sim$ 1 meV/hole. We demonstrate which of the located 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.