Interface resistance in ferromagnet/superconductor junctions

Results of theoretical study of spin-polarized tunneling in ferromagnet/superconductor junctions are presented. Spin and charge currents are calculated as a function of applied voltage and spin polarization in a ferromagnet. The model takes into account the splitting of different spin subbands in a ferromagnet and impurity scattering in the contact. The excess resistance of an FS contact due to the charge-imbalance in a superconductor is calculated for the first time. The results have implications for spin-coupled magnetoresistance in ferromagnet/superconductor contacts and for measuring spin polarization in ferromagnets.