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arXiv · 2303.13499

Detecting Bell correlations in multipartite non-Gaussian spin states

Jiajie Guo·Jordi Tura·Qiongyi He·Matteo Fadel
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Abstract

We expand the toolbox for studying Bell correlations in multipartite systems by introducing permutationally invariant Bell inequalities (PIBIs) involving few-body correlators. First, we present around twenty families of PIBIs with up to three- or four-body correlators, that are valid for arbitrary number of particles. Compared to known inequalities, these show higher noise robustenss, or the capability to detect Bell correlations in highly non-Gaussian spin states. We then focus on finding PIBIs that are of practical experimental implementation, in the sense that the associated operators require collective spin measurements along only a few directions. To this end, we formulate this search problem as a semidefinite program that embeds the constraints required to look for PIBIs of the desired form.

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Jiajie Guo, Jordi Tura, Qiongyi He, Matteo Fadel. 2023-03-23. Detecting Bell correlations in multipartite non-Gaussian spin states. https://doi.org/10.1103/physrevlett.131.070201

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