Fulde-Ferrel-Larkin-Ovchinnikov State due to Antisymmetric Spin-Orbit-Coupling in Noncentrosymmetric Superconductivity CePt$_3$Si

TL;DR

This paper explores the potential for FFLO states in noncentrosymmetric superconductor CePt$_3$Si caused by antisymmetric spin-orbit coupling, without external magnetic fields, highlighting conditions that stabilize such states.

Contribution

It introduces the possibility of FFLO states in spin triplet superconductors due to spin-orbit coupling, expanding understanding beyond magnetic field-induced scenarios.

Findings

FFLO state not realized in simple spherical Fermi surface models

Certain conditions can stabilize FFLO states in noncentrosymmetric superconductors

Potential realization of FFLO state in CePt$_3$Si without magnetic field

Abstract

When the inversion symmetry is broken, the spin-orbit coupling reduces the transition temperature of some types of spin triplet superconductivity, which is similar to the case that magnetic field reduces the spin singlet superconductivity due to Zeeman splitting. It is well known that Fulde-Ferrel-Larkin-Ovchinnikov (FFLO) state of spin singlet superconductivity is realized near the Pauli limit (or Chandrasekhar-Clogston limit) of external magnetic field. In FFLO state the amplitude of the order parameter is not uniform in space. In this paper we study the FFLO state in the spin triplet superconductivity in the absence of magnetic field due to the spin-orbit coupling. Although the FFLO state is not realized in the simple model with spherical Fermi surface, it will be stabilized if some condition is favorable for it. We discuss the possibility of FFLO state in CePt$_3$Si in the absence of external magnetic field.