Real-time Kadanoff-Baym approach to plasma oscillations in a correlated electron gas
A nonequilibrium Green's functions approach to the collective response of correlated Coulomb systems at finite temperature is presented. It is shown that solving Kadanoff-Baym type equations of motion for the two-time correlation functions with the external perturbing field included allows to compute the plasmon spectrum with collision effects in a systematic and consistent way. The scheme has ``built-in'' sum rule preservation and is simpler to implement numerically than the equivalent equilibrium approach based on the Bethe-Salpeter equation.
cond-mat.str-el↗