Complex-Stripe Phases Induced by Staggered Rashba Spin-Orbit Coupling

TL;DR

This paper investigates complex-stripe superconducting phases in multilayer systems with layer-dependent Rashba spin-orbit coupling, revealing a crossover between FF and LO phases and proposing CeCoIn_5 superlattices as a realization.

Contribution

It introduces the complex-stripe phase as an intermediate state between FF and LO phases in systems with staggered Rashba coupling, expanding understanding of superconducting phase behavior.

Findings

Identification of the complex-stripe phase in multilayer superconductors.

Demonstration of a crossover from FF to LO phases with temperature and magnetic field.

Proposal of CeCoIn_5 superlattices as a potential realization.

Abstract

We study superconducting phases in a quasi-two-dimensional multilayer system without local inversion symmetry. Broken local inversion symmetry induces layer-dependent Rashba-type spin-orbit couplings. We find that a complex-stripe phase, which is the intermediate phase between the Fulde-Ferrell (FF) phase and Larkin-Ovchinnikov (LO) phase, is realized in the magnetic field applied parallel to the layers. A crossover from the FF phase to the LO phase appears by tuning temperature and magnetic field. We show the local density of states that characterizes the complex-stripe phase. As a possible realization of the complex-stripe phase, we discuss the artificial superlattices of CeCoIn_5.