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Experimental violation of a spin-1 Bell inequality using maximally-entangled four-photon states

John C. Howell·Antia Lamas-Linares·Dik Bouwmeester
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Abstract

We demonstrate the first experimental violation of a spin-1 Bell inequality. The spin-1 inequality is a calculation based on the Clauser, Horne, Shimony and Holt formalism. For entangled spin-1 particles the maximum quantum mechanical prediction is 2.552 as opposed to a maximum of 2, predicted using local hidden variables. We obtained an experimental value of 2.27 $\pm 0.02$ using the four-photon state generated by pulsed, type-II, stimulated parametric down-conversion. This is a violation of the spin-1 Bell inequality by more than 13 standard deviations.

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John C. Howell, Antia Lamas-Linares, Dik Bouwmeester. 2001-05-29. Experimental violation of a spin-1 Bell inequality using maximally-entangled four-photon states. https://doi.org/10.1103/physrevlett.88.030401

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