Generalized uncertainty relations and entanglement dynamics in quantum Brownian motion models

TL;DR

This paper introduces a Wigner function propagator approach to analyze entanglement dynamics in quantum Brownian motion models, deriving generalized uncertainty relations that characterize environmental effects on system states.

Contribution

It provides a novel, intuitive method using the Wigner picture to derive master equations and uncertainty relations applicable to any number of oscillators and spectral densities.

Findings

Derived simple master equations for QBM models.

Established generalized uncertainty relations for initial states.

Analyzed entanglement creation, disentanglement, and decoherence across temperatures.

Abstract

We study entanglement dynamics in quantum Brownian motion (QBM) models. Our main tool is the Wigner function propagator. Time evolution in the Wigner picture is physically intuitive and it leads to a simple derivation of a master equation for any number of system harmonic oscillators and spectral density of the environment. It also provides generalized uncertainty relations, valid for any initial state that allow a characterization of the environment in terms of the modifications it causes to the system's dynamics. In particular, the uncertainty relations are very informative about the entanglement dynamics of Gaussian states, and to a lesser extent for other families of states. For concreteness, we apply these techniques to a bipartite QBM model, describing the processes of entanglement creation, disentanglement and decoherence at all temperatures and timescales.