Alzahrani A Z, Srivastava G P, Garg R, Migliorato M A
School of Physics, University of Exeter, Stocker Road, Exeter EX4 4QL, UK.
J Phys Condens Matter. 2009 Dec 2;21(48):485504. doi: 10.1088/0953-8984/21/48/485504. Epub 2009 Nov 11.
Based on ab initio calculations, we have investigated the atomic geometry, electronic properties and magnetic properties of Mn incorporation in GaAs. The inclusion of the Hubbard potential U in the calculation (namely with the σGGA+U scheme) results in the optimized geometry being contracted by approximately 2% relative to the relaxed geometry obtained by the (σGGA) method. Within both the σGGA and σGGA+U schemes the Mn impurity in bulk GaAs behaves like a d-hole with the majority spin state lying at 0.25 eV above the Fermi level. Theoretically simulated STM images for Mn/GaAs(110) indicate round protrusions at As sites and Ga sites, the latter being dependent on the Mn adsorption site (i.e. in different atomic layers). These results are supportive of a previous experimental STM image obtained with a very low Mn concentration.
