Unmasking the polygamous nature of quantum nonlocality.

Autor:	Cieśliński P; Institute of Theoretical Physics and Astrophysics, Faculty of Mathematics, Physics and Informatics, University of Gdańsk, Gdańsk 80-308, Poland., Knips L; Max Planck Institute for Quantum Optics, Garching 85748, Germany.; Faculty of Physics, Ludwig Maximilian University, Munich 80799, Germany.; Munich Center for Quantum Science and Technology, Munich 80799, Germany., Kowalczyk M; Institute of Theoretical Physics and Astrophysics, Faculty of Mathematics, Physics and Informatics, University of Gdańsk, Gdańsk 80-308, Poland., Laskowski W; Institute of Theoretical Physics and Astrophysics, Faculty of Mathematics, Physics and Informatics, University of Gdańsk, Gdańsk 80-308, Poland., Paterek T; Institute of Theoretical Physics and Astrophysics, Faculty of Mathematics, Physics and Informatics, University of Gdańsk, Gdańsk 80-308, Poland.; School of Mathematics and Physics, Department of Physics, Xiamen University Malaysia, Sepang 43900, Malaysia., Vértesi T; MTA Atomki Lendület Quantum Correlations Research Group, Institute for Nuclear Research, Debrecen 4001, Hungary., Weinfurter H; Institute of Theoretical Physics and Astrophysics, Faculty of Mathematics, Physics and Informatics, University of Gdańsk, Gdańsk 80-308, Poland.; Max Planck Institute for Quantum Optics, Garching 85748, Germany.; Faculty of Physics, Ludwig Maximilian University, Munich 80799, Germany.; Munich Center for Quantum Science and Technology, Munich 80799, Germany.
Jazyk:	angličtina
Zdroj:	Proceedings of the National Academy of Sciences of the United States of America [Proc Natl Acad Sci U S A] 2024 Oct 29; Vol. 121 (44), pp. e2404455121. Date of Electronic Publication: 2024 Oct 25.
DOI:	10.1073/pnas.2404455121
Abstrakt:	Quantum mechanics imposes limits on the statistics of certain observables. Perhaps the most famous example is the uncertainty principle. Similar trade-offs also exist for the simultaneous violation of multiple Bell inequalities. In the simplest case of three observers, it has been shown that if two observers violate a Bell inequality, then none of them can violate any Bell inequality with the third observer, a property called monogamy of Bell violations. Forms of Bell monogamy have been linked to the no-signaling principle, and the inability of simultaneous violations of all inequalities is regarded as their fundamental property. Here, we show that the Bell monogamy does not hold universally and that in fact the only monogamous situation exists for only three observers. Consequently, the nature of quantum nonlocality is truly polygamous. We present a systematic methodology for identifying quantum states, measurements, and tight Bell inequalities that do not obey the monogamy principle for any number of more than three observers. The identified polygamous inequalities enable any subset of [Formula: see text] observers to reveal nonlocality, which is also shown experimentally by measuring Bell-type correlations of six-photon Dicke states. Our findings may be exploited for multiparty quantum key distribution as well as simultaneous self-testing of multiple nodes in quantum networks. Competing Interests: Competing interests statement:The authors declare no competing interest.
Databáze:	MEDLINE
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