Recovering of superconductivity in S/F bilayers under spin-dependent nonequilibrium quasiparticle distribution

TL;DR

This paper theoretically investigates how spin-dependent nonequilibrium quasiparticle distributions can partially restore superconductivity in superconductor/ferromagnet bilayers, counteracting the usual suppression caused by ferromagnetic proximity.

Contribution

It introduces the concept that spin accumulation can recover superconductivity in S/F bilayers, providing a new perspective on controlling superconductivity via spin-dependent distributions.

Findings

Spin accumulation can counteract ferromagnetic suppression of superconductivity.

Partial recovery of superconductivity is achievable with realistic parameters.

A potential experimental setup for observing this effect is proposed.

Abstract

We study theoretically the influence of spin accumulation on superconductivity in a superconductor/ferromagnet bilayer. It is well-known that the superconductivity in S/F bilayers is suppressed by the proximity to a ferromagnet. The spin accumulation by itself is also a depairing factor. But here we show that creation of the spin accumulation on top of effective exchange depairing, caused by the proximity to a ferromagnet, can lead to an opposite result. The superconductivity can be partially recovered by spin-dependent quasiparticle distribution. The systems with realistic parameters are considered and the possible experimental setup is proposed.