Hexagonal pnictide SrPtAs: superconductivity with locally broken inversion symmetry

TL;DR

This paper investigates the effects of local inversion symmetry breaking in the hexagonal superconductor SrPtAs, revealing significant enhancements in spin susceptibility and paramagnetic limiting field due to spin-orbit coupling.

Contribution

It demonstrates how local inversion symmetry breaking influences superconductivity in SrPtAs, highlighting the role of spin-orbit coupling in this material.

Findings

Enhanced spin susceptibility in SrPtAs

Increased paramagnetic limiting field

Local inversion symmetry breaking impacts superconductivity

Abstract

Unlike other pnictides, SrPtAs has a hexagonal structure, containing layers with As-Pt atoms that form a honeycomb lattice. These layers lack inversion symmetry which allows for a spin-orbit coupling that we show has a dramatic effect on superconductivity in this material. In particular, for conventional s-wave superconductivity in SrPtAs, both the spin susceptibility and the paramagnetic limiting field are enhanced significantly with respect to that usually expected for s-wave superconductors. SrPtAs provides a prime example of a superconductor with locally broken inversion symmetry.