Effective band model of giant magnetoresistance

We consider the transport properties in magnetic multilayers for electronic current in the plane of the surfaces. The model is based on the effective s-band construction for the multilayer consisting of the metallic spacer an d two ferromagnetic layers characterized by s-d coupling. We discuss the qu asielectron spectrum in its effective mass approximation, with the perturba tion taken into account by the effective potential, which also includes the interface contributions. We find the energy dispersion and the Fermi level for the effective s-band corm-non for electrons in the whole sample. The r esults are equivalent in fact to those obtained within the Hood-Falicov mod el, but they seem to us much simpler and more transparent for their extensi ons and applications.