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arXiv · 1403.1964

Generation of macroscopic singlet states in a cold atomic ensemble

N. Behbood·F. Martin Ciurana·G. Colangelo·M. Napolitano·Geza Toth·R. J. Sewell·M. W. Mitchell
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Abstract

We report the generation of a macroscopic singlet state in a cold atomic sample via quantum non-demolition (QND) measurement induced spin squeezing. We observe 3 dB of spin squeezing and detect entanglement of up to $5.5\times10^5 $ atoms with $5\sigma$ statistical significance using a generalized spin squeezing inequality. The degree of squeezing implies at least 50% of the atoms have formed singlets, while the response to a magnetic field gradient indicates entanglement bonds at all length scales, a characteristic of quantum spin liquids.

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N. Behbood, F. Martin Ciurana, G. Colangelo, M. Napolitano, Geza Toth, R. J. Sewell, M. W. Mitchell. 2014-03-08. Generation of macroscopic singlet states in a cold atomic ensemble. https://doi.org/10.1103/physrevlett.113.093601

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