Bell Correlations in a Bose-Einstein Condensate
Abstract
Characterizing many-body systems through the quantum correlations between their constituent particles is a major goal of quantum physics. Although entanglement is routinely observed in many systems, we report here the detection of stronger correlations - Bell correlations - between the spins of about 480 atoms in a Bose-Einstein condensate. We derive a Bell correlation witness from a many-particle Bell inequality involving only one- and two-body correlation functions. Our measurement on a spin-squeezed state exceeds the threshold for Bell correlations by 3.8 standard deviations. Our work shows that the strongest possible non-classical correlations are experimentally accessible in many-body systems, and that they can be revealed by collective measurements.
Cite
@article{arxiv.1604.06419,
title = {Bell Correlations in a Bose-Einstein Condensate},
author = {Roman Schmied and Jean-Daniel Bancal and Baptiste Allard and Matteo Fadel and Valerio Scarani and Philipp Treutlein and Nicolas Sangouard},
journal= {arXiv preprint arXiv:1604.06419},
year = {2016}
}
Comments
20 pages, 6 figures, including supplementary information