Spin transport and magnetoresistance in ferromagnet/superconductor/ ferromagnet spin valves

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. © 2005 The American Physical Society.