Dynamical structure factor for s-f model with spin-phonon interaction

A Green's function technique is used to study the effects of spin-phonon interaction in ferromagnetic semiconductors based on the s-f model. The spin wave energy and the damping are evaluated for the first time beyond the RPA and numerically calculated. They increase with increasing spin-phonon interaction. The dependence of the dynamical structure factor on temperature and on spin-phonon interaction is discussed. At fixed T with increasing spin-phonon interaction the peak height decreases, the half-width increases, whereas the peak shifts to higher energy values.