Third-order many-body perturbation theory applied to Kondo-type dynamics in diluted magnetic semiconductors

Ultrafast magnetization dynamics in diluted magnetic semiconductors is investigated using a model based on the pseudofermion formalism and a third-order many-particle expansion of the exact pd exchange interaction. Dynamical RKKY-like interactions and double-exchange mechanism based on the Kondo interaction emerge naturally from our approach. Our analysis reveals that the many-particle expansion is not generally well defined and an infrared Kondo-like divergence can occur. In particular, the bare polarization propagator fails to converge in the presence of a highly confined hole gas and an enhancement of the ion-hole spin correlation is found for low-dimensional systems. Finally, numerical simulations have been performed on GaMnAs and show that dynamical many-particle correlations play a significant role in the time evolution of the total magnetization.