CPP- Giant Magnetoresistance and Thermo-Electric Power of multilayers

Oscillations of magnetoresistance and thermo-electric power (TEP) vs. both nonmagnetic spacer as well as ferromagnetic slab thicknesses are studied in the current-perpendicular-to-plane (CPP) geometry, in terms of a single-band tight-binding model. The spin-dependent conductance has been calculated from the Kubo formula by means of a recursion Green's function technique, and the $ TEP $ directly from the well-known Onsager relations. In general, the observed oscillations may have either just one or two periods. In the latter case the long period of oscillations, related to spectacular beats, is apparently of non-RKKY type. The relative TEP oscillations are strongly enhanced in comparison with those of the giant magnetoresistance, have the same periods, but different phases and a negative bias.