Crossed surface flat bands of Weyl semimetal superconductors

TL;DR

This paper reveals that Weyl semimetal superconductors can host crossed flat bands on their surfaces due to Fermi arcs, with a topological origin and potential experimental detection methods.

Contribution

It introduces a new type of surface state with crossed flat bands in Weyl semimetal superconductors, explaining their topological stability and symmetry requirements.

Findings

Crossed flat bands are supported by Fermi arcs in Weyl semimetal superconductors.

The topological origin and symmetry stabilization of the crossed flat bands are clarified.

Possible experimental detection via tunneling spectroscopy is discussed.

Abstract

It has been noted that certain surfaces of Weyl semimetals have bound states forming open Fermi arcs, which are never seen in typical metallic states. We show that the Fermi arcs enable them to support an even more exotic surface state with crossed flat bands in the superconducting state. We clarify the topological origin of the crossed flat bands and the relevant symmetry that stabilizes the cross point. We also discuss their possible experimental verification by tunneling spectroscopy.