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arXiv · 1207.3314

Atomic nonclassicality quasiprobabilities

T. Kiesel·W. Vogel·S. L. Christensen·J. -B. Béguin·J. Appel·E. S. Polzik
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Abstract

Although nonclassical quantum states are important both conceptually and as a resource for quantum technology, it is often difficult to test whether a given quantum system displays nonclassicality. A simple method to certify nonclassicality is introduced, based on easily accessible collective atomic quadrature measurements, without the need of full state tomography. The statistics is analyzed beyond the ground-state noise level, by direct sampling of a regularized atomic quadrature quasiprobability. Nonclassicality of a squeezed ensemble of 2x10^5 Cesium atoms is demonstrated, with a significance of up to 23 standard deviations.

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T. Kiesel, W. Vogel, S. L. Christensen, J. -B. Béguin, J. Appel, E. S. Polzik. 2012-10-08. Atomic nonclassicality quasiprobabilities. https://doi.org/10.1103/physreva.86.042108

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