Possible Realization of Topological Crystalline Superconductivity with Time-Reversal Symmetry in UTe2

TL;DR

This paper explores the potential for topological crystalline superconductivity in UTe2, focusing on how crystalline symmetries can protect Majorana surface states despite the material's trivial topological classification.

Contribution

It demonstrates that topological crystalline superconductivity can exist in UTe2 across all odd-parity pairing states, expanding the understanding of topological phases in this material.

Findings

Majorana surface states protected by mirror and rotational symmetries.

Topological invariants identified for all odd-parity pairing states.

Topological crystalline superconductivity possible despite trivial 3D topology.

Abstract

The recent measurement of the de Haas-van Alphen effect in the spin-triplet superconductor UTe2 [D. Aoki et al., J. Phys. Soc. Jpn. 91, 083704 (2022)] supports cylindrical electron and hole Fermi surfaces, which implies that UTe2 is trivial as a 3D time-reversal-invariant topological superconductor. Inspired by this observation, we investigate the possible realization of a topological crystalline superconductor protected by the crystalline symmetry of UTe2. We examine Majorana surface states protected by mirror and two-fold rotational symmetries for all symmetry-allowed odd-parity pairing states with time-reversal symmetry and clarify the corresponding topological invariants. It is found that topological crystalline superconductivity can be realized for all irreducible representations of odd-parity pairing states of UTe2 even for cylindrical Fermi surfaces.