Closing objectivity loophole in Bell tests on a public quantum computer

Abstract:We have constructed and run a Bell test of local realism focusing on the objectivity criterion. Objectivity means that the outcomes are confirmed macroscopically by a few observers at each party. The IBM Quantum and IonQ devices turn out to be sufficiently accurate to pass such an extended Bell-type test, although at the price of communication loopholes and residual but statistically significant signaling. The test also serves as the benchmark of entanglement spread across larger sets of qubits.

arXiv:2506.08940 [quant-ph]

(or arXiv:2506.08940v3 [quant-ph] for this version)

https://doi.org/10.48550/arXiv.2506.08940 Focus to learn more arXiv-issued DOI via DataCite

https://doi.org/10.1002/qute.70420 Focus to learn more DOI(s) linking to related resources

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