System-environment correlations and non-Markovian dynamics

作者：Pernice A^*; Helm J; Strunz W T

来源：Journal of Physics B: Atomic, Molecular and Optical Physics , 2012, 45(15): 154005.

DOI：10.1088/0953-4075/45/15/154005

We determine the total state dynamics of a dephasing open quantum system using the standard environment of harmonic oscillators. Of particular interest are random unitary approaches to the same reduced dynamics and system-environment correlations in the full model. Concentrating on a model with an at times negative dephasing rate, the issue of 'non-Markovianity' will also be addressed. Crucially, given the quantum environment, the appearance of non-Markovian dynamics turns out to be accompanied by a loss of system-environment correlations. Depending on the initial purity of the qubit state, these system-environment correlations may be purely classical over the whole relevant time scale, or there may be intervals of genuine system-environment entanglement. In the latter case, we see no obvious relation between the build-up or decay of these quantum correlations and 'non-Markovianity'.

• 出版日期2012-8-14