Non-local interactions in moir\'e Hubbard systems

TL;DR

This paper explores how non-local interactions in moiré Hubbard systems can be tuned to realize exotic quantum states such as spin liquids, ferromagnets, and superconductors, highlighting their potential as versatile quantum simulators.

Contribution

It provides a theoretical framework showing how to control non-local interaction terms in moiré materials to access novel many-body phases.

Findings

Non-local interactions are significant in moiré Hubbard systems.

Tuning interaction strengths can stabilize exotic quantum states.

Potential realization of spin liquids, ferromagnets, and superconductors.

Abstract

Moir\'e materials formed in two-dimensional semiconductor heterobilayers are quantum simulators of Hubbard-like physics with unprecedented electron-density and interaction-strength tunability. Compared to atomic scale Hubbard-like systems, electrons or holes in moir\'e materials are less strongly attracted to their effective lattice sites because these are defined by finite-depth potential extrema. As a consequence, non-local interaction terms like interaction-assisted hopping and intersite-exchange are more relevant. We theoretically demonstrate the possibility of tuning the strength of these coupling constants to favor unusual states of matter, including spin liquids, insulating ferromagnets, and superconductors.