Spin susceptibility in superconductors without inversion symmetry

TL;DR

This paper investigates how antisymmetric spin-orbit coupling affects the spin susceptibility in non-centrosymmetric superconductors, focusing on CePt3Si, and finds minimal susceptibility change along certain directions regardless of pairing symmetry.

Contribution

It provides a theoretical analysis of spin susceptibility behavior in non-inversion symmetric superconductors, especially CePt3Si, considering various pairing symmetries.

Findings

Weak change in spin susceptibility along the c-axis

Intermediate reduction in basal plane susceptibility

Implications for paramagnetic limiting in CePt3Si

Abstract

In materials without spatial inversion symmetry the spin degeneracy of the conduction electrons can be lifted by an antisymmetric spin-orbit coupling. We discuss the influence of this spin-orbit coupling on the spin susceptibility of such superconductors, with a particular emphasis on the recently discovered heavy Fermion superconductor CePt3Si. We find that, for this compound (with tetragonal crystal symmetry,) irrespective of the pairing symmetry, the stable superconducting phases would give a very weak change of the spin susceptibility for fields along the c-axis and an intermediate reduction for fields in the basal plane. We also comment on the consequences for the paramagnetic limiting in this material.