Prospects and limitations for short-range pairing in lighlty doped twisted transition metal dichalcogenides heterobilayers

Twisted transition metal dichalcogenides bilayers display and rich phase diagram, featuring Mott insulators, generalized Wigner crystals, and quantum anomalous Hall insulators, which can all be studied in situ with high tunability using nearby metallic gates. Recently, the so-called three-particle mechanism for electronic pairing was introduced, and shown to mediate effective attractive interactions between doped charges added above such insulating states. This mechanism becomes exact in the limit of low doping concentrations, where it can mediate superconductivity provided the level of disorder remains sufficiently low.

In this talk, we investigate possible pairing above the Mott insulating states of twisted transition metal dichalcogenides heterobilayers within the three-particle mechanism. We find that it provides an odd effective pairing interaction in AB stacked bilayers, which favors a superconducting order parameter similar to the B-phase of superfluid Helium. In AA stacked bilayer, it rather promotes a robust and fully gapped singlet order. We investigate the robustness of these superconducting state against the long-range part of the interactions, and show that they only appear for sufficiently screened Coulomb potentials.