Scattering anisotropy and giant magnetoresistance in magnetic multilayers

We present full ab initio calculations of giant magnetoresistance (GMR) in Co/Cu (001) multilayers including self-consistent impurity scattering poten tials. Starting from density functional theory the electronic structure of the multilayer and the scattering at impurities are described by means of a new Green function method. It will be demonstrated that impurity scatterin g in magnetic multilayers is strongly anisotropic in comparison to impurity scattering in bulk systems. Concerning transport the anisotropy of scatter ing leads to a formation of highly conducting channels which give rise to s hort circuits and cause strong variation of GMR as a function of the impuri ty position in the multilayer. (C) 2001 American Institute of Physics.