Quantum entanglement in the spatial symmetry breaking phase transition of a driven-dissipative Bose-Hubbard dimer

TL;DR

This paper investigates quantum correlations and entanglement in a driven-dissipative Bose-Hubbard dimer near a symmetry-breaking phase transition, combining semiclassical, Gaussian, and numerical methods.

Contribution

It provides a detailed analysis of quantum entanglement behavior at the bifurcation point in a dissipative Bose-Hubbard dimer, including finite density effects.

Findings

Large quantum correlations near bifurcation points

Peak in logarithmic entanglement negativity at criticality

Agreement between Gaussian and numerical approaches

Abstract

We theoretically explore quantum correlation properties of a dissipative Bose-Hubbard dimer in presence of a coherent drive. In particular, we focus on the regime where the semiclassical theory predicts a bifurcation with a spontaneous spatial symmetry breaking. The critical behavior in a well defined thermodynamical limit of large excitation numbers is considered and analyzed within a Gaussian approach. The case of a finite boson density is also examined by numerically integrating the Lindblad master equation for the density matrix. We predict the critical behavior around the bifurcation points accompanied with large quantum correlations of the mixed steady-state, in particular exhibiting a peak in the logarithmic entanglement negativity.