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Quantum correlations are critical to our understanding of nature, with far-reaching technological and fundamental impact. These often manifest as violations of Bells inequalities, bounds derived from the assumptions of locality and realism, concepts integral to classical physics. Many tests of Bells inequalities have studied pairs of correlated particles; however, the immense interest in multi-particle quantum correlations is driving the experimental frontier to test systems beyond just pairs. All experimental violations of Bells inequalities to date require supplementary assumptions, opening the results to one or more loopholes, the closing of which is one of the most important challenges in quantum science. Individual loopholes have been closed in experiments with pairs of particles and a very recent result closed the detection loophole in a six ion experiment. No experiment thus far has closed the locality loopholes with three or more particles. Here, we distribute three-photon Greenberger-Horne-Zeilinger entangled states using optical fibre and free-space links to independent measurement stations. The measured correlations constitute a test of Mermins inequality while closing both the locality and related freedom-of-choice loopholes due to our experimental configuration and timing. We measured a Mermin parameter of 2.77 +/- 0.08, violating the inequality bound of 2 by over 9 standard deviations, with minimum tolerances for the locality and freedom-of-choice loopholes of 264 +/- 28 ns and 304 +/- 25 ns, respectively. These results represent a significant advance towards definitive tests of the foundations of quantum mechanics and practical multi-party quantum communications protocols.
Entanglement swapping entangles two particles that have never interacted[1], which implicitly assumes that each particle carries an independent local hidden variable, i.e., the presence of bilocality[2]. Previous experimental studies of bilocal hidde
Non-locality stands nowadays not only as one of the cornerstones of quantum theory, but also plays a crucial role in quantum information processing. Several experimental investigations of nonlocality have been carried out over the years. In spite of
It is shown that the ensemble ${p (alpha),|alpha>|alpha^*>}$ where $p (alpha)$ is a Gaussian distribution of finite variance and $| alpha>$ is a coherent state can be better discriminated with an entangled measurement than with any local strategy sup
Contextuality and nonlocality are non-classical properties exhibited by quantum statistics whose implications profoundly impact both foundations and applications of quantum theory. In this paper we provide some insights into logical contextuality and
We show that for all $nge3$, an example of an $n$-partite quantum correlation that is not genuinely multipartite nonlocal but rather exhibiting anonymous nonlocality, that is, nonlocal but biseparable with respect to all bipartitions, can be obtained