Anisotropic magneto-resistance in a GaMnAs-based single impurity tunnel   diode: a tight binding approach
  Using an advanced tight-binding approach, we estimate the anisotropy of the tunnel transmission associated with the rotation of the 5/2 spin of a single Mn atom forming an acceptor state in GaAs and located near an AlGaAs tunnel barrier. Significant anisotropies in both in-plane and out-of-plane geometries are found, resulting from the combination of the large spin-orbit coupling associated with the p-d exchange interaction, cubic anisotropy of heavy-hole dispersion and the low C2v symmetry of the chemical bonds. 
M.O. Nestoklon, O. Krebs, H. Jaffr\`es, S. Ruttala, J.-M. George,   J.-M. Jancu and P. Voisin
cond-mat.mes-hall