English

Nematic, chiral and topological superconductivity in transition metal dichalcogenides

Superconductivity 2025-03-26 v2 Strongly Correlated Electrons

Abstract

We introduce and study a realistic model for superconductivity in twisted bilayer WSe2_{2}, where electron pairing arises from spin-valley fluctuations in the weak-coupling regime. Our model comprises both the full continuum model moir\'{e} bandstructure and a short-ranged repulsive interaction. By calculating the spin-valley susceptibility, we identify a Fermi surface nesting feature near half-filling of the top-most moir\'{e} band, which induces significantly enhanced spin-valley fluctuations. We then analyze the dominant Kohn-Luttinger pairing instabilities due to these spin-valley fluctuations and show that the leading instability corresponds to a two-component order parameter, which can give rise to nematic, chiral and topological superconductivity. As our findings are asymptotically exact for small interaction strengths, they provide a viable starting point for future studies of superconductivity in twisted transition metal dichalcogenide bilayers.

Keywords

Cite

@article{arxiv.2110.10172,
  title  = {Nematic, chiral and topological superconductivity in transition metal dichalcogenides},
  author = {Constantin Schrade and Liang Fu},
  journal= {arXiv preprint arXiv:2110.10172},
  year   = {2025}
}