Anisotropic magnetic responses of topological crystalline superconductors

TL;DR

This paper investigates how crystalline symmetry influences the magnetic response of Majorana Kramers pairs in topological crystalline superconductors, revealing symmetry-based constraints on their topological properties.

Contribution

It provides a theoretical framework linking crystalline symmetry to the direction of Majorana Ising spins and topological invariants in superconductors.

Findings

Crystalline symmetry determines Majorana Ising spin directions.

Conditions for nontrivial topological invariants under rotational symmetry.

Constraints on topological invariants derived from symmetry considerations.

Abstract

Majorana Kramers pairs emerged on surfaces of time-reversal-invariant topological crystalline superconductors show the Ising anisotropy to an applied magnetic field. We clarify that crystalline symmetry uniquely determines the direction of the Majorana Ising spin for given irreducible representations of pair potential, deriving constraints to topological invariants. Besides, necessary conditions for nontrivial topological invariants protected by the n-fold rotational symmetry are shown.