Electron intersection and spin accumulation in spin polarized tunneling

We discuss the effect of electron interaction and spin accumulation on spin polarized tunneling. Charges of opposite magnitude are induced on opposite sides of the insulator. There is a splitting between the spin up and spin down bands which produces an additional contribution to the magnetoresistance. The ratio between the splitting and the current is an effective resistance, R(s). The difference between R(s) on opposite sides of the junction is of the order of (much less than) the interfacial resistance when the magnetization of the ferromagnets are parallel (antiparallel) to each other. The signal to background ratio for the change in R(s) between the parallel and the antiparallel configuration is much bigger than that for the resistance. This R(s) (k Ohm) is much larger in magnitude than that (approximate to 10(-5) Ohm) observed in metallic trilayers and thus maybe-of practical interest for applications. (C) 1996 American Institute of Physics.