Angular Dependence of Giant Magnetoresistance in Magnetic Multilayered Structures

We present an analytical quantum-statistical theory of the angular variation of the giant magnetoresistance (GMR) in magnetic multilayers (current flowing in the plane of the layers) which takes into account both spin-dependent scattering of conduction electrons and spin-dependent potential barriers between successive layers. We show that the widely accepted linear variation of the GMR with the cosine of the angle between the magnetizations in the successive ferromagnetic layers is valid when the GMR originates from a spin-dependent scattering mechanism without potential barriers between layers. In the presence of potential barriers, the angular variation of the GMR can be much more complex.