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Related papers: Violating Bell's inequality beyond Cirel'son's bou…

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It is pointed out that the local hidden variables model of Bell and Clauser-Horne-Shimony-Holt (CHSH) gives $|<B>|\leq 2\sqrt{2}$ or $|<B>|\leq 2$ for the quantum CHSH operator $B={\bf a}\cdot {\bf \sigma}\otimes ({\bf b}+{\bf…

Quantum Physics · Physics 2012-07-03 Kazuo Fujikawa

We discuss the relations between the violation of the CHSH Bell inequality for systems of two qubits on the one side and entanglement of formation, local filtering operations, and the entropy and purity on the other. We calculate the…

Quantum Physics · Physics 2009-11-07 Frank Verstraete , Michael M. Wolf

Scalable quantum computing relies on high-quality, long-range entanglement, a challenge on noisy, near-term devices. The need for practical insights for near-term algorithm design calls for trade-offs exploration in implementing dynamic…

Quantum Physics · Physics 2025-07-16 Jean-Baptiste Waring , Christophe Pere , Sébastien Le Beux

We find that Bell's inequality can be significantly violated (up to Tsirelson's bound) with two-mode entangled coherent states using only homodyne measurements. This requires Kerr nonlinear interactions for local operations on the entangled…

Quantum Physics · Physics 2007-06-13 Magdalena Stobińska , Hyunseok Jeong , Timothy C. Ralph

Any n-qubit state with n independent perfect correlations is equivalent to a graph state. We present the optimal Bell inequalities for perfect correlations and maximal violation for all classes of graph states with n < 7 qubits. Twelve of…

Quantum Physics · Physics 2009-11-13 Adan Cabello , Otfried Gühne , David Rodriguez

Free will (or randomness) has been studied to achieve loophole-free Bell's inequality test and to provide device-independent quantum key distribution security proofs. The required randomness such that a local hidden variable model (LHVM)…

Quantum Physics · Physics 2017-03-29 Yifeng Teng , Shenghao Yang , Siwei Wang , Mingfei Zhao

Connecting incompatibility in measurements with the violation of local realism is one of the fundamental avenues of research. For two qubits, any incompatible pair of projective measurements can violate Clauser-Horne-Shimony-Holt (CHSH)…

Quantum Physics · Physics 2024-11-19 Sudipta Mondal , Pritam Halder , Saptarshi Roy , Aditi Sen De

A long-standing problem in the foundations of quantum mechanics is to identify a physical principle that explains why algebraically maximal violations of Bell inequalities can generally not be achieved in Nature. One recently proposed…

Quantum Physics · Physics 2026-03-24 Lionel J. Dmello , David Gross

We present a formalization of several fundamental notions and results from Quantum Information theory, including density matrices and projective measurements, along with the proof that the local hidden-variable hypothesis advocated by…

Quantum Physics · Physics 2023-06-23 Mnacho Echenim , Mehdi Mhalla

The first part of this paper contains an introduction to Bell inequalities and Tsirelson's theorem for the non-specialist. The next part gives an explicit optimum construction for the "hard" part of Tsirelson's theorem. In the final part we…

Quantum Physics · Physics 2015-05-13 David Avis , Sonoko Moriyama , Masaki Owari

The experimental data on the helicity amplitudes of charmonium decays allow us to measure entanglement in final state spin correlations and test possible violations of the Bell inequality. We find that the Bell inequality is violated with a…

High Energy Physics - Phenomenology · Physics 2024-07-03 M. Fabbrichesi , R. Floreanini , E. Gabrielli , L. Marzola

Clauser-Horne-Shimony-Holt inequality for bipartite systems of 4-dimension is studied in detail by employing the unbiased eight-port beam splitters measurements. The uniform formulae for the maximum and minimum values of this inequality for…

Quantum Physics · Physics 2007-05-23 Li-Bin Fu , Jing-Ling Chen , Shi-Gang Chen

Bell inequality violation is one of the most widely known manifestations of entanglement in quantum mechanics; indicating that experiments on physically separated quantum mechanical systems cannot be given a local realistic description.…

Quantum Physics · Physics 2007-05-23 Yeong-Cherng Liang , Andrew C. Doherty

Quantum nonlocality of several four-qubit states is investigated by constructing a new Bell inequality. These include the Greenberger-Zeilinger-Horne (GHZ) state, W state, cluster state, and the state $|\chi>$ that has been recently…

Quantum Physics · Physics 2013-05-29 Chunfeng Wu , Ye Yeo , L. C. Kwek , C. H. Oh

We prove, modulo a conjecture on quantum steering ellipsoids being true, the existence of the phenomenon of locally inaccessible hidden quantum correlations. That is, the existence of two-particle states whose hidden quantum correlations…

Quantum Physics · Physics 2024-12-23 Andrés F. Ducuara , Cristian E. Susa , Paul Skrzypczyk

For the maximal violation of all Bell inequalities by an arbitrary pure two-qudit state of any dimension, we derive a new lower bound expressed via the concurrence of this pure state. This new lower bound and the upper bound on the maximal…

Quantum Physics · Physics 2023-08-17 Elena R. Loubenets , Sergey Kuznetsov , Louis Hanotel

Nonlocality is a fascinating and counterintuitive aspect of Nature, revealed by the violation of a Bell inequality. The standard and easiest configuration in which Bell inequalities can be measured has been proposed by…

Quantum Physics · Physics 2015-03-17 Enrico Pomarico , Jean-Daniel Bancal , Bruno Sanguinetti , Anas Rochdi , Nicolas Gisin

We present new bell inequalities for arbitrary dimensional bipartite quantum systems. The maximal violation of the inequalities is computed. The Bell inequality is capable of detecting quantum entanglement of both pure and mixed quantum…

Quantum Physics · Physics 2015-05-27 Ming Li , Shao-Ming Fei , Xianqing Li-Jost

The CHSH mod 3 Bell inequality is a natural testbed for higher-dimensional quantum nonlocality, yet its maximal quantum violation and self-testing properties have remained unresolved. We determine its exact maximal quantum value and show…

Optimization and Control · Mathematics 2026-04-07 Igor Klep , Nando Leijenhorst , Victor Magron

We describe a protocol for generating random numbers based on the existence of quantum violations of a free Clauser-Horne-Shimony-Holt inequality, namely CHSH-3. Our method uses semidefinite programming relaxations to compute such…

Quantum Physics · Physics 2020-07-31 Don Jean Baptiste Anoman , François Arnault , Simone Naldi
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