The dynamics of a typical open quantum system, namely a quantum Brownian particle in a harmonic potential, is studied focusing on its non-Markovian regime. Both an analytic approach and a stochastic wave-function approach are used to describe the exact time evolution of the system. The border between two very different dynamical regimes, the Lindblad and non-Lindblad regimes, is identified and the relevant physical variables governing the passage from one regime to the other are singled out. The non-Markovian short-time dynamics is studied in detail by looking at the mean energy, the squeezing, the Mandel parameter, and the Wigner function of the system.
Maniscalco, S., Piilo, J., Intravaia, F., Petruccione, F., & Messina, A. (2004). Lindblad- and non-Lindblad-type dynamics of a quantum Brownian particle. Physical Review A, 70(3), . https://doi.org/10.1103/PhysRevA.70.032113