Nonequilibrium Superconductivity near Spin Active Interfaces
  The Riccati formulation of the quasiclassical theory of nonequilibrium superconductors is developed for spin-dependent scattering near magnetic interfaces. We derive boundary conditions for the Riccati distribution functions at a spin-active interface that are applicable to a wide range of nonequilibrium transport properties of hybrid systems of superconducting and magnetic materials. We use these results to calculate spin, charge and heat transport for normal metal-ferromagnet-superconductor (NFS) and superconducting-ferromagnetic-superconducting (SFS) point contacts. 
Erhai Zhao, Tomas Lofwander, and J. A. Sauls