Coupling of electronic charge and spin at a ferromagnetic-paramagnetic metal interface

Microscopic models are presented to elucidate the concept of interfacial charge-spin coupling. At the interface between a ferromagnet and a paramagnet, the spin subbands are loosely coupled, an interfacial conductance may be defined for each, and a result of their inequivalence is that an electric current flowing from a ferromagnetic metal into a paramagnetic metal will be partially spin polarized, i.e., will have an associated current of magnetization. The inverse is also true; nonequilibrium magnetization present in a paramagnetic metal can be detected as an open circuit voltage across an interface between the paramagnet and a ferromagnet. Using this effect, a new technique to measure conduction electron relaxation times is described.