Topological chiral superconductivity from antiferromagnetic correlations in moir\'{e} bands with extreme spin-orbit coupling

TL;DR

This paper explores topological chiral superconductivity in moiré bands influenced by strong spin-orbit coupling and antiferromagnetic interactions, revealing novel pairing states and their topological nature relevant to twisted bilayer WSe2.

Contribution

It introduces a multi-orbital $t$-$J$ model capturing the interplay of spin-orbit coupling and antiferromagnetism, identifying topological chiral pairing states in moiré materials.

Findings

Preferred pairing states are associated with $^{1,2}E$ representations.

Chiral superconducting states are topological, confirmed by Wilson loop calculations.

Results connect moiré superconductivity with bulk quantum materials phenomena.

Abstract

Motivated by the strong-correlation phenomenology observed near the superconducting phase in twisted bilayer WSe$_2$, we study multi-orbital $t$-$J$ models that are derived from different parameter regimes. The models contain effective antiferromagnetic interactions that are influenced by the strong underlying spin-orbit coupling. The possible superconducting pairing states are investigated in these models. We find that the preferred pairing order parameters are associated with the $^{1,2}E$ representations of the three-fold rotation symmetry operator $C_3$, with the $p\pm i p$ component intermixing with the $d\pm id$ component. The chiral superconducting states are shown to be topological, based on the Wilson loops of the corresponding Bogoliubov quasiparticles. We discuss the implications of our findings for experimental observations, as well as the new connections our results uncover between the moir\'{e} superconductivity and its counterpart in bulk quantum materials.