Higher-order topological superconductivity in type-II time-reversal-symmetric Weyl semimetals with a hybrid pairing

TL;DR

This paper demonstrates that type-II time-reversal-symmetric Weyl semimetals can host higher-order topological superconductivity with hybrid pairing states, revealing surface-dependent pairing and hinge states as key features.

Contribution

It introduces a self-consistent analysis of hybrid s-wave and p-wave pairing in type-II Weyl semimetals, highlighting their potential for topological superconductivity.

Findings

Hybrid pairing is surface-dependent, with s-wave on bottom and p-wave on top surfaces.

The superconducting state exhibits second-order topological features with hinge states.

Type-II Weyl semimetals are promising platforms for unconventional topological superconductivity.

Abstract

We employed the self-consistent method on a two-orbital type-II time-reversal-symmetric Weyl semimetal, revealing a hybrid pairing of singlet $s$-wave and triplet $p$-wave. We present a detailed analysis of the normal-state electronic structure and the self-consistent results. Our findings indicate that the selection of hybrid pairings is governed by distinct surface Fermi-arc configurations: specifically, $s$-wave pairing dominates on the bottom surface, while $p$-wave pairing prevails on the top. Furthermore, the emergent superconducting state is a second-order topological superconductors with hinge states in the system. Our results identify type-II time-reversal-invariant Weyl semimetals as a promising intrinsic platform for realizing unconventional and topological superconductivity.