The conductance quantization and Andreev reflection of narrow ferromagnet/superconductor point contacts are theoretically studied. We show that the conductance quantization and the Andreev reflection depend on whether the contact region is superconducting or ferromagnetic as well as on the strength of the exchange field in the ferromagnet. The Andreev reflection of the ferromagnetic contact is more suppressed than that of the superconducting contact. We also show that the conductance-voltage curve has a bump at zero bias voltage if there is no interfacial scattering. On the contrary, the conductance-voltage curve shows a dip if the system has an interfacial scattering.

• Received 26 July 2001

DOI:https://doi.org/10.1103/PhysRevB.65.020508