Abstract

The effects of photo - excitation and spin wave scattering on magnetic specific heat of the diluted magnetic semiconductor (DMS) (Ga, Mn)As are theoretically studied using Green function formalism and employing a model system Hamiltonian consisting of magnons, photons and an interaction of magnons with photons. At very low temperatures, the DMS is found to have anomalous magnetic specific heat. This could be interpreted as the material is in non - equilibrium situation due to fluctuation effects undergoing heat losses. The specific heat is found to decrease with increase in magnetic impurity concentration and further decreases in the presence of the magnon-photon interaction. On the other hand, in the presence of magnon-scattering it is shown to increase rapidly at relatively higher temperatures.

Key words: (Ga, Mn)As DMS, photo - excitation, spin wave scattering, magnetization, heat capacity.