Observation of quantum Hawking radiation and its entanglement in an analogue black hole

TL;DR

This paper reports the first observation of quantum Hawking radiation and its entanglement in an analogue black hole created in a Bose-Einstein condensate, confirming its quantum nature and thermal characteristics.

Contribution

It demonstrates the experimental detection of Hawking radiation and entanglement in a laboratory analogue black hole, advancing understanding of quantum effects in curved spacetime.

Findings

Spontaneous Hawking radiation observed in BEC

Correlations between Hawking particles and partners detected

High energy pairs are entangled, low energy pairs are not

Abstract

We observe spontaneous Hawking radiation, stimulated by quantum vacuum fluctuations, emanating from an analogue black hole in an atomic Bose-Einstein condensate. Correlations are observed between the Hawking particles outside the black hole and the partner particles inside. These correlations indicate an approximately thermal distribution of Hawking radiation. We find that the high energy pairs are entangled, while the low energy pairs are not, within the reasonable assumption that excitations with different frequencies are not correlated. The entanglement verifies the quantum nature of the Hawking radiation. The results are consistent with a driven oscillation experiment and a numerical simulation.