Kinetic theory of anisotropic magnetoresistance in copper

The anisotropic magnetoresistance (MR) in Copper (Cu) is studied, using kinetic theory and a simplified Fermi surface with necks. Cu's Fermi surface has "necks" located in the <111> direction. If the electron, which circulate perpendicular to the applied magnetic field, hits the "neck", then it cannot complete a closed orbit with a definite curvature sign, and cannot contribute to the electronic conduction. The number of conducting electrons depends on the field orientation relative to the Cu crystal. Our theoretical model explains the observed striking anisotropy with MR reaching 450 in some orientation.