The spin dynamics of a single Mn atom in a laser driven CdTe quantum dot is
addressed theoretically. Recent experimental
results\cite{Le-Gall_PRL_2009,Goryca_PRL_2009,Le-Gall_PRB_2010}show that it is
possible to induce Mn spin polarization by means of circularly polarized
optical pumping. Pumping is made possible by the faster Mn spin relaxation in
the presence of the exciton. Here we discuss different Mn spin relaxation
mechanisms. First, Mn-phonon coupling, which is enhanced in the presence of the
exciton. Second, phonon-induced hole spin relaxation combined with carrier-Mn
spin flip coupling and photon emission results in Mn spin relaxation. We model
the Mn spin dynamics under the influence of a pumping laser that injects
excitons into the dot, taking into account exciton-Mn exchange and phonon
induced spin relaxation of both Mn and holes. Our simulations account for the
optically induced Mn spin pumping.Comment: 17 pages, 11 figures, submitted to PR
