Coherence oscillations between weakly coupled Bose-Hubbard dimers

TL;DR

This paper predicts a novel entropy oscillation mode in two weakly-coupled Bose-Hubbard dimers, where one-particle coherence oscillates without particle or energy transfer, explained through a semiclassical approach.

Contribution

It introduces the concept of purity oscillations in coupled Bose-Hubbard dimers and provides a semiclassical explanation for this new dynamical phenomenon.

Findings

Prediction of a novel entropy oscillation mode.

Demonstration of coherence transfer without particle or energy transfer.

Semiclassical explanation of the purity oscillation phenomenon.

Abstract

We study theoretically the dynamics of two weakly-coupled Bose-Josephson junctions, prepared with the same particle number $N$ and Josephson excitation number $\nu$ but with different reduced one-particle purity $\gamma$. A novel entropy oscillation mode is predicted, in which one-particle coherence is transferred between the Bose-Hubbard dimers with no particle or energy transfer. We explain this purity oscillation using a semiclassical picture.