A model of Josephson Junctions on Boson Systems - Currents and Entropy Production Rate -

TL;DR

This paper models Josephson junctions in boson systems with Bose-Einstein condensation, analyzing non-equilibrium steady states, entropy production, and Josephson currents using C*-algebraic methods.

Contribution

It introduces a C*-algebraic framework to study non-equilibrium steady states in boson systems with BEC, highlighting conditions for entropy production and Josephson currents.

Findings

Mean entropy production rate is always positive when reservoir parameters differ.

Josephson currents can occur without entropy production under identical reservoir conditions.

The model provides insights into quantum transport phenomena in bosonic systems.

Abstract

Non-equilibrium steady states (NESS), in the sense of D. Ruelle, of Boson systems with Bose--Einstein condensation (BEC) are investigated with the aid of the C^*-algebraic method. The model consists of a quantum particle and several bosonic reservoirs. We show that the mean entropy production rate is strictly positive, independent of phase differences provided that the temperatures or the chemical potentials of reservoirs are different. Moreover, Josephson currents occur without entropy production, if the temperatures and the chemical potentials of reservoirs are identical.