Non-Markovian dynamics and entanglement in quantum Brownian motion

Eduardo Souza Fraga, Gastão I. Krein, L. F. Palhares

Jyrki Piilo, Sabrina Maniscalco, Francesco Petruccione +1 more

Werner Koch, Frank Großmann, Joachim Ankerhold +1 more

Sabrina Maniscalco, Jyrki Piilo, Kalle‐Antti Suominen

Christian Hörhammer, H. Büttner

We study the non-Markovian decoherence and disentanglement dynamics of dissipative quantum systems with special emphasis on non-Gaussian continuous variable systems. The dynamics are described by the Hu–Paz–Zhang master equation of quantum Brownian motion. The time evolution of the decoherence function of a single-mode superposition is compared to the concurrence of a two-mode entangled state. It is verified that moderate non-Markovian influences slow down the decay of interference fringes and quantum correlations, while strong non-Markovian effects resulting from an out-of-resonance bath can even accelerate the loss of coherence, compared to predictions of Markovian approximations. Qualitatively different scenarios including exponential, Gaussian or algebraic decay of the decoherence function are analyzed. It is shown that partial revivals of coherence can occur in case of non-Lindblad-type dynamics.

Guglielmo Pellitteri, Vittorio Giovannetti, Vasco Cavina

We analyze the exact dynamics of a generalized quantum Brownian motion model, employing Gaussian master equation methods. We demonstrate that, by modulating the relative weights of specific interaction channels, we can control the degree of non-Markovianity of the system, and induce a transition from non-Markovian to Markovian regimes. The non-Markovianity of the evolution is formally characterized by leveraging the Gorini--Kossakowski--Sudarshan--Lindblad theorem and by employing quantitative measures of information backflow. Finally, we clarify the physical mechanism behind the phenomenology of this model, thereby providing a systematic platform for environment engineering through the strategic tuning of dissipation channels.