Unconventional superconductivity and anomalous response in hole-doped transition metal dichalcogenides

TL;DR

This paper reports the discovery of an unconventional superconducting phase in hole-doped transition metal dichalcogenides, characterized by mixed spin pairing, stability under magnetic fields, and topologically nontrivial excitations influenced by light.

Contribution

It introduces a novel superconducting pairing state in 2D TMDs with unique spin, valley, and topological properties, expanding understanding of correlated phases in these materials.

Findings

Unconventional superconducting phase with mixed spin singlet and triplet pairing.

Superconductivity stable against large in-plane magnetic fields.

Topological quasiparticle excitations accessible via circularly polarized light.

Abstract

Two-dimensional transition metal dichalcogenides entwine interaction, spin-orbit coupling, and topology. Hole-doped systems lack spin degeneracy: states are indexed with spin and valley specificity. This unique structure offers new possibilities for correlated phases and phenomena. We realize an unconventional superconducting pairing phase which is an equal mixture of a spin singlet and the $m = 0$ spin triplet. It is stable against large in-plane magnetic fields, and its topology allows quasiparticle excitations of net nonzero Berry curvature via pair-breaking circularly polarized light.