Expansion formulas for quantum master equations including initial correlation
Sachiko Kitajima, Masashi Ban, Fumiaki Shibata · Journal of Physics A Mathematical and Theoretical · 2017
Abstract The quantum master equation is considered for an open system initially correlated with a thermal reservoir, where the initial correlation is created by an initial preparation of a relevant system. Perturbative expansion formulas for quantum master equations are systematically derived with respect to a system-reservoir interaction. The result is applied to the dispersive JC model and the spin-boson model. In the second order approximation, the generalized Bloch equations for a spin system are found. It is shown that the effect of the initial correlation between the spin and the thermal reservoir is equivalent to an effective external field applied to the spin system.