Dynamics of entanglement in a dissipative Bose-Hubbard dimer

TL;DR

This paper explores how entanglement and coherence evolve in a dissipative Bose-Hubbard dimer, linking quantum phenomena to classical phase space, and shows how localized dissipation can enhance entanglement.

Contribution

It provides a detailed analysis connecting semiclassical phase space with quantum entanglement dynamics, including analytical approximations and the impact of dissipation.

Findings

Entanglement dynamics are dominated by beats among three eigenstates near fixed points.

Persistent entangled states occur only near self-trapping fixed points.

Localized dissipation can significantly enhance entanglement.

Abstract

We study the connection between the semiclassical phase space of the Bose--Hubbard dimer and inherently quantum phenomena in this model, such as entanglement and dissipation-induced coherence. Near the semiclassical self-trapping fixed points, the dynamics of EPR entanglement and condensate fraction consists of beats among just three eigenstates. Since persistent EPR entangled states arise only in the neighborhood of these fixed points, our analysis explains essentially all of the entanglement dynamics in the system. We derive accurate analytical approximations by expanding about the strong-coupling limit; surprisingly, their realm of validity is nearly the entire parameter space for which the self-trapping fixed points exist. Finally, we show significant enhancement of entanglement can be produced by applying localized dissipation.