Topological versus conventional superconductivity in a Weyl semimetal: A microscopic approach

TL;DR

This paper develops a microscopic model to compare conventional and topological superconductivity in Weyl semimetals, deriving phase diagrams, critical temperatures, and low-temperature behaviors to identify experimental signatures of topological quantum criticality.

Contribution

It introduces a microscopic framework for analyzing both conventional and monopole pairing in Weyl semimetals, deriving self-consistent equations and phase diagrams.

Findings

Identified conditions favoring topological versus conventional pairing.

Calculated critical temperatures for both superconducting phases.

Predicted specific heat behavior as an experimental probe.

Abstract

Starting from a microscopic model for the particle-particle interactions in a Weyl semimetal, we analyzed the possibility for conventional as well as monopole Cooper pairing between quasiparticle excitations at the same (intra-nodal) or opposite (inter-nodal) Weyl nodes. We derived a coupled system of self-consistent BCS-like equations, where the angular dependence of the pairings is directly determined from the microscopic interaction symmetries. We studied the competition between conventional and monopole superconducting phases, thus obtaining explicitly the phase diagrams from the microscopic interaction model parameters. We determined the critical temperatures for both phases, and the low temperature critical behavior, including the specific heat, that we suggest as possible experimental probe for topological quantum criticality in Weyl semimetals.