Transport in Ferromagnet/Superconductor Spin Valves

We consider transport in realistic Ferromagnet-Superconductor layered nanostructures with a spin-valve structure: $F_1/N/F_2/S$ where $F_1$ and $F_2$ denote the ferromagnets, $S$ the superconductor, and $N$ a normal metal spacer usually inserted in these spin-valve devices. These systems exhibit physically intricate proximity effects, including singlet to triplet conversion, which have a large impact on the transport properties and the spin-valve effect. We use a fully self consistent method that ensures that all conservation laws are satisfied. We obtain results for the conductance, $G$, of the devices as a function of voltage, for all values of the angle $\phi$ between the magnetizations of the $F_1$ and $F_2$ layers. These calculations are performed for experimentally relevant ranges of layer thicknesses, material properties, and interfacial scattering. We consider also spin currents and spin transfer torques in these structures.