Spin transport and magnetoresistance in F/S/F spin valves

TL;DR

This paper investigates spin transport and relaxation mechanisms in superconductor-based F/S/F spin valves, analyzing how different spin-flip processes affect magnetoresistance and providing numerical results for Co/Al/Co systems.

Contribution

It introduces a detailed analysis of spin relaxation due to spin-orbit interaction and magnetic impurities within the quasiclassical framework, applied to Co/Al/Co spin valves.

Findings

Energy dependence of spin-flip rate differs for spin-orbit and magnetic impurity mechanisms.

Interface resistances can be negligible compared to bulk resistances in Co/Al/Co systems.

Numerical calculations show temperature and Al length influence magnetoresistance.

Abstract

We consider spin transport and spin relaxation in superconductors using the quasiclassical theory of superconductivity. We include spin relaxation due to spin-orbit interaction as well as magnetic impurities, and show that the energy dependence of the spin-flip rate is different for these two mechanisms. In ferromagnet-superconductor-ferromagnet systems made of Co and Al, interface resistances can be small compared to bulk resistances. This simplifies the description of transport in Co/Al/Co spin valves, for which we numerically calculate the temperature and Al length dependence of the magnetoresistance.