Theory of correlated insulators and superconductor at ν = 1 in twisted WSe2
Sunghoon Kim, Juan Felipe Mendez-Valderrama, Xuepeng Wang, Debanjan Chowdhury
Abstract
The observation of a superconducting phase, an intertwined insulating phase, and a continuous transition between the two at a commensurate filling of ν = 1 in bilayers of twisted WSe2 at θ = 3.650 raises a number of intriguing questions about the origin of this phenomenology. Here we report the possibility of a displacement-field induced continuous transition between a superconductor and a quantum spin-liquid Mott insulator at ν = 1, starting with a simplified three-orbital model of twisted WSe2, including on-site, nearest-neighbor density-density interactions, and a chiral-exchange interaction, respectively. By employing parton mean-field theory, we discuss the nature of these correlated insulators, their expected evolution with the displacement-field, and their phenomenological properties. Recently, superconductivity intertwined with an insulating phase at a commensurate band-filling was discovered in twisted bilayer WSe2. Here, the authors theoretically propose that the observed insulating state may be a quantum spin-liquid Mott insulator with electron fractionalization, separated from the superconductor via a quantum phase transition.