  Starting with a microscopic model based on the Kohn-Luttinger Hamiltonian and
kinetic p-d exchange combined with Boltzmann formula for conductivity we
identify the scattering from magnetic Mn combined with the strong spin-orbit
interaction of the GaAs valence band as the dominant mechanism of the
anisotropic magnetoresistance (AMR) in (Ga,Mn)As. This fact allows to construct
a simple analytical model of the AMR consisting of two heavy-hole bands whose
charge carriers are scattered on the impurity potential of the Mn atoms. The
model predicts the correct sign of the AMR (resistivity parallel to
magnetization is smaller than perpendicular to magnetization) and identifies
its origin arising from the destructive interference between electric and
magnetic part of the scattering potential of magnetic ionized Mn acceptors when
the carriers move parallel to the magnetization.
