Metal-insulator transition in transition metal dichalcogenide heterobilayer: accurate treatment of interaction

Transition metal dichalcogenide superlattices provide an exciting new platform for exploring and understanding a variety of phases of matter. The moiré continuum Hamiltonian, of two-dimensional jellium in a modulating potential, provides a fundamental model for such systems. Strong interaction and correlation effects are crucial ingredients for much of the interesting physics in moiré materials. However, there is a lack of accurate and efficient computational methods for including them. We use quantum Monte Carlo (QMC) methods to accurately include the effect of interaction and explore its interplay with details of the moiré potential (arXiv 2306.14954). We find important differences from existing results by Hartree-Fock and exact diagonalization studies. In addition, we compare hybrid density-functional theory (DFT) predictions to our QMC results. The QMC data provide accurate characterizations of the phase diagram as a function of density and moiré potential depth. We find interesting phases with magnetic and charge correlations which differ from predictions based on independent electron methods.