Monogamy and backflow of mutual information in non-Markovian thermal baths

(Dated: July 24, 2014)We investigate the dynamics of information among the parties of tripartite systems. We startby proving two results concerning the monogamy of mutual information. The first one states thatmutual information is monogamous for generic tripartite pure states. The second shows that, ingeneral, mutual information is monogamous only if the amount of genuine tripartite correlations islarge enough. Then, we analyze the internal dynamics of tripartite systems whose parties do notexchange energy. In particular, we allow for one of the subsystems to play the role of a finite thermalbath. As a result, we find a typical scenario in which local information tends to be converted intodelocalized information. Moreover, we show that (i) the information flow is reversible for finitethermal baths at low temperatures, (ii) monogamy of mutual information is respected throughoutthe dynamics, and (iii) genuine tripartite correlations are typically present. Finally, we analyticallycalculate a quantity capable of revealing favorable regimes for non-Markovianity in our model.