The magneto-crystalline anisotropy (MCA) of (Ga,Mn)As films has been studied on the basis of ab-initio electronic structure theory by performing magnetic torque calculations. An appreciable contribution to the in-plane uniaxial anisotropy can be attributed to an extended region adjacent to the surface. Calculations of the exchange tensor allow to ascribe a significant part to the MCA to the exchange anisotropy, caused either by a tetragonal distortion of the lattice or by the presence of the surface or interface.
@article{arxiv.1108.5870,
title = {Spin-orbit coupling effect in (Ga,Mn)As films: anisotropic exchange interactions and magnetocrystalline anisotropy},
author = {S. Mankovsky and S. Polesya and S. Bornemann and J. Minár and F. Hoffmann and C. H. Back and H. Ebert},
journal= {arXiv preprint arXiv:1108.5870},
year = {2015}
}