Non-Markovian decoherence and disentanglement scenarios in quantum Brownian motion

TL;DR

This paper investigates how non-Markovian effects influence decoherence and entanglement decay in quantum Brownian motion, revealing that moderate effects slow decay while strong effects can accelerate it, with various decay patterns and possible coherence revivals.

Contribution

It provides a detailed analysis of non-Markovian decoherence and disentanglement dynamics in non-Gaussian continuous variable systems using the Hu-Paz-Zhang master equation, highlighting new decay behaviors and coherence revival phenomena.

Findings

Moderate non-Markovian effects slow decoherence and entanglement loss.

Strong non-Markovian effects can accelerate decoherence compared to Markovian models.

Different decay patterns (exponential, Gaussian, algebraic) are observed, with possible coherence revivals.

Abstract

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.