Magnetic Multilayers: Quasiclassical Transport Via the Kubo Formula

A real‐space quantum approach, based on the Kubo formula, is used to describe the quasiclassical transport behavior of metallic multilayers. We emphasize the differences between the cases of current in the plane of the layers, for which size effects play a dominant role and current perpendicular to the planes, for which we provide several proofs that the so‐called series resistor model holds for all length scales