Weyl Phases in Point-Group Symmetric Superconductors

TL;DR

This paper investigates the topological properties of superconductivity in Weyl semimetals with point-group symmetry, revealing protected nodes and surface states influenced by Fermi surface topology and symmetry-breaking effects.

Contribution

It introduces a topological invariant based on point-group eigenvalues and links it to Fermi surface topology in superconducting Weyl semimetals.

Findings

Identification of topologically protected bulk nodes and surface Fermi arcs.

Derivation of a topological invariant from point-group eigenvalues.

Analysis of surface orientation and strain effects on surface states.

Abstract

We study superconductivity in a Weyl semimetal with broken time-reversal symmetry and stabilized by a point-group symmetry. The resulting superconducting phase is characterized by topologically protected bulk nodes and surface states with Fermi arcs. The topological invariant governing the system is calculated using changes in eigenvalues of the point-group operator along high-symmetry momentum lines. We show that this invariant is determined by the Fermi surface topology of the Weyl semimetal. We discuss the effect of surface orientation and $C_4$-breaking strain as possible experimental consequences.