Entropy production and the role of correlations in quantum Brownian motion

We perform a study on quantum entropy production, different kinds of correlations, and their interplay in the driven Caldeira-Leggett model of quantum Brownian motion. The model, taken with a large but finite number of bath modes, is exactly solvable, and the assumption of a Gaussian initial state leads to an efficient numerical simulation of all desired observables in a wide range of model parameters. Our paper is composed of three main parts. We first compare two popular definitions of entropy production, namely, the standard weak-coupling formulation originally proposed by Spohn [J. Math. Phys. 19, 1227 (1978)] and later on extended to the driven case by Deffner and Lutz [Phys. Rev. Lett. 107, 140404 (2011)], and the always-positive expression introduced by Esposito, Lindenberg and van den Broeck [New J. Phys. 12, 013013 (2010)], which relies on the knowledge of the evolution of the bath. As a second study, we explore the decomposition of the Esposito et al. entropy production into system-environment and intraenvironment correlations for different ranges of couplings and temperatures. Lastly, we examine the evolution of quantum correlations between the system and the environment, measuring entanglement through logarithmic negativity.

Automated summary

In this study, we examined quantum entropy production, different types of correlations, and their interplay in the driven Caldeira-Leggett model of quantum Brownian motion. We compared two definitions of entropy production and explored system-environment correlations, intraenvironment correlations, and the evolution of quantum entanglement between the system and the environment. This research provides insights into the dynamics of quantum systems and their interactions with their environment.