The short-time and long-time behaviors of non-Markovianity measure using two-time correlation functions in open quantum systems

摘要

We investigate non-Markovianity measure using two-time correlation functionsfor open quantum systems. We define non-Markovianity measure as the differencebetween the exact two-time correlation function and the one obtained in theMarkov limit. Such non-Markovianity measure can easily be measured inexperiments. We found that the non-Markovianity dynamics in different timescale crucially depends on the system-environment coupling strength and otherphysical parameters such as the initial temperature of the environment and theinitial state of the system. In particular, we obtain the short-time andlong-time behaviors of non-Markovianity for different spectral densities. Wealso find that the thermal fluctuation always reduce the non-Markovian memoryeffect. Also, the non-Markovianity measure shows non-trivial initial statedependence in different time scales.