TMDs as a platform for spin liquid physics: A strong coupling study of twisted bilayer WSe2

Abstract

The advent of twisted moiré heterostructures as a playground for strongly correlated electron physics has led to a plethora of experimental and theoretical efforts seeking to unravel the nature of the emergent superconducting and insulating states. Among these layered compositions of two-dimensional materials, transition metal dichalcogenides are now appreciated as highly tunable platforms to simulate reinforced electronic interactions in the presence of low-energy bands with almost negligible bandwidth. Here, we focus on the twisted homobilayer WSe2 and the insulating phase at half-filling of the flat bands reported therein. More specifically, we explore the possibility of realizing quantum spin liquid (QSL) physics on the basis of a strong coupling description, including up to second-nearest neighbor Heisenberg couplings J1 and J2 as well as Dzyaloshinskii–Moriya (DM) interactions. Mapping out the global phase diagram as a function of an out-of-plane displacement field, we indeed find evidence for putative QSL states, albeit only close to SU(2) symmetric points. In the presence of finite DM couplings and XXZ anisotropy, long-range order is predominantly present with a mix of both commensurate and incommensurate magnetic phases.