0-pi transition in SFS junctions with strongly spin-dependent scattering

TL;DR

This paper develops a theoretical model for superconductor-ferromagnetic alloy-superconductor trilayers, revealing how strong spin-dependent scattering influences the proximity effect and critical current oscillations.

Contribution

It introduces a new theory accounting for strong spin-dependent scattering in GMR alloy-based SFS junctions, explaining oscillation behavior and decay of the critical current.

Findings

Critical current oscillates with ferromagnetic layer thickness.

Oscillation period is related to Fermi velocity and exchange energy.

Critical current decays exponentially with mean free path.

Abstract

We develop theory of proximity effect in a superconductor - GMR alloy - superconductor trilayers, which takes into account strong spin dependence of electron scattering of compositional disorder in a diluted ferromagnetic alloy. We show that in such a system the critical current oscillations as the function of the thickness of the ferromagnetic layer, with the period of $v_{F}/2I$, decay exponentially with the characteristic length of the order of the mean free path.