Dissipation induced coherence and stochastic resonance of an open two-mode Bose-Einstein condensate

TL;DR

This paper explores how dissipation and noise can enhance coherence and induce stochastic resonance in an open two-mode Bose-Einstein condensate, revealing counterintuitive effects of environment-induced dynamics.

Contribution

It demonstrates the phenomenon of dissipation-induced coherence and stochastic resonance in a many-particle quantum system, supported by Monte Carlo simulations and theoretical analysis.

Findings

Maximal phase coherence occurs at an optimal dissipation rate.

Dissipation combined with strong interactions restores condensate purity.

Monte Carlo simulations qualitatively agree with theoretical predictions.

Abstract

We discuss the dynamics of a Bose-Einstein condensate in a double-well trap subject to phase noise and particle loss. The phase coherence of a weakly-interacting condensate, experimentally measured via the contrast in an interference experiment, as well as the response to an external driving become maximal for a finite value of the dissipation rate matching the intrinsic time scales of the system. This can be understood as a stochastic resonance of the many-particle system. Even stronger effects are observed when dissipation acts in concurrence with strong inter-particle interactions, restoring the purity of the condensate almost completely and increasing the phase coherence significantly. Our theoretical results are backed by Monte Carlo simulations, which show a good qualitative agreement and provide a microscopic explanation for the observed stochastic resonance effect.