Interaction range and temperature dependence of symmetry breaking in strongly correlated two-dimensional moir\'e transition metal dichalcogenide bilayers

TL;DR

This paper explores how the range of electron-electron interactions and temperature influence symmetry breaking in strongly correlated two-dimensional moiré TMD bilayers, revealing multiple symmetry-broken ground states at various fillings.

Contribution

It provides a theoretical analysis of the effects of interaction range and temperature on symmetry breaking in moiré TMD bilayers, highlighting controllable experimental parameters.

Findings

Symmetry breaking depends on interaction range and temperature.

Multiple ground states exist at various rational fillings.

Thermal suppression of symmetry breaking occurs above a critical temperature.

Abstract

We theoretically consider two-dimensional moir\'e transition metal dichalcogenide (TMD) bilayers, which are strongly correlated in the sense that the on-site Coulomb interaction is comparable to or larger than the hopping kinetic energy between the moir\'e lattice sites. The system accommodates many symmetry-broken ground states both in charge and isospin sectors at various commensurate rational fillings such as 1/2, 1/3, 1/4, 2/3, etc. We investigate two complementary important aspects of the dependence of the symmetry breaking on (1) the range of the electron-electron interaction, which can in principle be experimentally controlled by the nearby gates and the dielectric environment, and (2) temperature, which could thermally suppress the symmetry breaking above a critical temperature. Experimental implications of the theory are discussed.