Domain wall superconductivity in superconductor/ferromagnet bilayers

TL;DR

This paper investigates how magnetic domain walls in ferromagnets can locally enhance superconductivity in superconductor/ferromagnet bilayers, especially when the domain wall thickness matches the superconducting coherence length.

Contribution

It provides a theoretical analysis of the impact of magnetic domain walls on the critical temperature of superconductor/ferromagnet bilayers, highlighting the conditions for significant enhancement.

Findings

Localized superconducting states form near domain walls.

Superconducting critical temperature can be significantly increased.

Effect is strongest when domain wall thickness is comparable to coherence length.

Abstract

We analyze the enhancement of the superconducting critical temperature of superconducting/ferromagnetic bilayers due to the appearance of localized superconducting states in the vicinity of magnetic domain walls in the ferromagnet. We consider the case when the main mechanism of the superconductivity destruction via the proximity effect is the exchange field. We demonstrate that the influence of the domain walls on the superconducting properties of the bilayer may be quite strong if the domain wall thickness is of the order of superconducting coherence length.