Violation of Bell inequalities in an analogue black hole

TL;DR

This paper investigates quantum entanglement and Bell inequality violations in an analogue black hole system created in a Bose-Einstein condensate, revealing maximally entangled long wavelength modes and potential for observing quantum correlations.

Contribution

It demonstrates the violation of Bell inequalities in an analogue black hole, highlighting the presence of robust multi-mode quantum entanglement in the system.

Findings

Maximal entanglement of long wavelength modes

Violation of bipartite and tripartite Bell inequalities

Observation of superpositions akin to Greenberger-Horne-Zeilinger states

Abstract

Signals of entanglement and nonlocality are quantitatively evaluated at zero and finite temperature in an analogue black hole realized in the flow of a quasi one-dimensional Bose-Einstein condensate. The violation of Lorentz invariance inherent to this analog system opens the prospect to observe 3-mode quantum correlations and we study the corresponding violation of bipartite and tripartite Bell inequalities. It is shown that the long wavelength modes of the system are maximally entangled, in the sense that they realize a superposition of continuous variable versions of Greenberger-Horne-Zeilinger states whose entanglement resists partial tracing.