Transport in ferromagnet/superconductor spin valves

Abstract

We consider charge transport properties in realistic, fabricable, Ferromagnet/Superconductor spin valves having a layered structure $F_1/N/F_2/S$, where $F_1$ and $F_2$ denote the ferromagnets, $S$ the superconductor, and $N$ the normal metal spacer usually inserted in actual devices. Our calculation is fully self-consistent, as required to ensure that conservation laws are satisfied. We include the effects of scattering at all the interfaces. We obtain results for the device conductance $G$, as a function of bias voltage, for all values of the angle $\phi$ between the magnetizations of the $F_1$ and $F_2$ layers and a range of realistic values for the material and geometrical parameters in the sample. We discuss, in the context of our results for $G$, the relative influence of all parameters on the spin valve properties. We study also the spin current and the corresponding spin transfer torque in $F_1/F_2/S$ structures.