The role of the reservoir correlations in the relaxation rates for different coupling models

A quantal system is assumed to interact with a thermal environment. The fully coupled (FC) and the rotating wave approximation (RWA) models are considered to derive a generalized master equation for the reduced density operator in terms of the spectral density of the correlation function of the thermal environment. The parameters of the irreversible motion are compared for different reservoir models. In particular, we examine the case of normal and odd heat baths and work out specific examples for both coupling mechanisms