Thermodynamic entropy production in the dynamical Casimir effect

TL;DR

This paper investigates how thermodynamic entropy evolves in the dynamical Casimir effect, linking entropy production to quantum coherence and entanglement through short- and long-term analyses of a quantum field in a cavity.

Contribution

It introduces two approaches to analyze entropy production, connecting it to quantum coherence and entanglement, providing a comprehensive understanding of the dynamical Casimir effect's thermodynamics.

Findings

Entropy scales with particle number in short-time limit.

Entropy relates to quantum coherence within the field modes.

Long-time entropy production links to mode entanglement.

Abstract

This paper address the question of thermodynamic entropy production in the context of the dynamical Casimir effect. Specifically, we study a scalar quantum field confined within a one-dimensional ideal cavity subject to time-varying boundary conditions dictated by an externally prescribed trajectory of one of the cavity mirrors. The central question is how the thermodynamic entropy of the field evolves over time. Utilizing an effective Hamiltonian approach, we compute the entropy production and reveal that it exhibits scaling behavior concerning the number of particles created in the short-time limit. Furthermore, this approach elucidates the direct connection between this entropy and the emergence of quantum coherence within the mode basis of the field. In addition, by considering a distinct approach based on the time evolution of Gaussian states we examine the long-time limit of entropy production within a single mode of the field. This approach results in establishing a connection between the thermodynamic entropy production in a single field mode and the entanglement between that particular mode and all other modes. Consequently, by employing two distinct approaches, we comprehensively address both the short-term and long-term dynamics of the system. Our results thus link the irreversible dynamics of the field, as measured by entropy production and induced by the dynamical Casimir effect, to two fundamental aspects of quantum mechanics: coherence and entanglement.