Signatures of triplet correlations in density of states of Ising superconductors

TL;DR

This paper investigates how triplet correlations influence the density of states in disordered Ising superconductors, revealing that triplet components can significantly broaden the density of states beyond effects of magnetic field and disorder.

Contribution

It provides a detailed phase diagram and analyzes the impact of triplet pairing on the density of states in disordered TMD monolayers under magnetic fields.

Findings

Triplet correlations significantly broaden the density of states.

Triplet components can increase the critical magnetic field.

Rich phase diagram with competing and cooperating order parameters.

Abstract

The few-layer transition metal dichalcogenides (TMDs) have been recently suggested as a platform for controlled unconventional superconductivity. We study the manifestations of unconventional triplet pairing in the density of states of a disordered TMD based monolayer. The conventional singlet pairing attraction is assumed to be the dominant pairing interaction. We map the phase diagrams of disordered Ising superconductors in the plane of temperature and the in-plane magnetic field. The latter suppresses singlet and promote triplet correlations. The triplet order parameters of a trivial (non-trivial) symmetry compete (cooperate) with the singlet order parameter which gives rise to a rich phase diagram. We locate the model-dependent phase boundaries and compute the order parameters in each of the distinct phases. With this information, we obtain the density of states by solving the Gorkov equation. The triplet components of the order parameters may change an apparent width of the density of states by significantly increasing the critical field. The triplet components of the order parameters lead to the density of states broadening significantly exceeding the broadening induced by magnetic field and disorder in the singlet superconductor.