A UNIFIED SEMICLASSICAL THEORY OF PARALLEL AND PERPENDICULAR GIANT MAGNETORESISTANCE IN METALLIC SUPERLATTICES

The giant magnetoresistance effect in magnetic superlattices for the c urrent perpendicular to and in the layer planes is studied within a un ified semiclassical approach that is based on the Boltzmann equation w ith exact boundary conditions for the spin-dependent distribution func tions of electrons, interface processes responsible for the magnetores istance are found to be different in these geometries, and this can re sult in an essential difference in general behaviour between the in-pl ane magnetoresistance and the perpendicular-plane one. A correlation b etween the giant magnetoresistance and the multilayer magnetization is also discussed.