Spin-polarized tunneling in ferromagnet/unconventional superconductor junctions

We study tunneling in ferromagnet/unconventional superconductor (F/S) junctions. We include the effects of spin polarization, interfacial resistance, and Fermi wave-vector mismatch between the F and S regions. Andreev reflection at the F/S interface, governing tunneling at low bias voltage, is strongly modified by these parameters. The conductance exhibits a wide variety of novel features as a function of applied voltage.