Topological properties of spin-triplet superconductors and the Fermi surface topology in the normal state

TL;DR

This paper explores the relationship between topological invariants of spin-triplet superconductors and the Fermi surface topology in their normal state, providing a method to compute these invariants and linking Fermi surface features to surface states.

Contribution

It introduces an efficient method to calculate topological invariants in spin-triplet superconductors and establishes a direct connection between Fermi surface topology and surface states.

Findings

Topological invariants are linked to Fermi surface structures.

A new computational method for Z2 invariants and winding number.

Fermi surface topology correlates with gapless surface states.

Abstract

We report intimate relations between topological properties of full gapped spin-triplet superconductors with time-reversal invariance and the Fermi surface topology in the normal states. An efficient method to calculate the Z2 invariants and the winding number for the spin-triplet superconductors is developed, and connections between these topological invariants and the Fermi surface structures in the normal states are pointed out. We also obtain a correspondence between the Fermi surface topology and gapless surface states in the superconducting states. The correspondence is inherent to spin-triplet superconductivity.