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Related papers: A Geometric Picture of Entanglement and Bell Inequ…

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We provide a method to describe quantum nonlocality for $n$-qubit systems. By treating the correlation function as an $n$-index tensor, we derive a generalized Bell inequality. Taking generalized Greenberger-Horne-Zeilinger (GHZ) state for…

Quantum Physics · Physics 2021-05-11 Dong Ding , Yingqiu He , Fengli Yan , Ting Gao

In device-independent quantum information processing Bell inequalities are not only used as detectors of nonlocality, but also as certificates of relevant quantum properties. In order for these certificates to work, one very often needs…

Quantum Physics · Physics 2019-11-06 Remigiusz Augusiak , Alexia Salavrakos , Jordi Tura , Antonio Acín

Two kinds of Bell-states diagonal (BSD) entanglement witnesses (EW) are constructed by using the algebra of Dirac $\gamma$ matrices in the space-time of arbitrary dimension $d$, where the first kind can detect some BSD relativistic and…

Quantum Physics · Physics 2009-11-13 M. A. Jafarizadeh , R. Sufiani

Higgs boson decays produce pairs of $W$ bosons in a maximally entangled state, the spins of which can be expected to violate Bell inequalities. We show that the spin density matrix of the $W^\pm$ pair may be reconstructed experimentally…

High Energy Physics - Phenomenology · Physics 2022-07-27 Alan Barr

We observe violation of a Bell inequality between the quantum states of two remote Yb ions separated by a distance of about one meter with the detection loophole closed. The heralded entanglement of two ions is established via interference…

Quantum Physics · Physics 2008-05-20 D. N. Matsukevich , P. Maunz , D. L. Moehring , S. Olmschenk , C. Monroe

We discuss the use of the Gilbert algorithm to tailor entanglement witnesses for unextendibleproduct basis bound entangled states (UPB BE states). The method relies on the fact that an optimalentanglement witness is given by a plane…

Quantum Physics · Physics 2020-01-22 Marcin Wieśniak , Palash Pandya , Omer Sakarya , Bianka Woloncewicz

We report the measurement of a Bell inequality violation with a single atom and a single photon prepared in a probabilistic entangled state. This is the first demonstration of such a violation with particles of different species. The…

Quantum Physics · Physics 2008-12-03 D. L. Moehring , M. J. Madsen , B. B. Blinov , C. Monroe

Detection and quantification of entanglement in quantum resources are two key steps in the implementation of various quantum-information processing tasks. Here, we show that Bell-type inequalities are not only useful in verifying the…

Quantum Physics · Physics 2011-02-28 Yeong-Cherng Liang , Tamas Vertesi , Nicolas Brunner

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

We have determined the maximum quantum violation of 241 tight bipartite Bell inequalities with up to five two-outcome measurement settings per party by constructing the appropriate measurement operators in up to six-dimensional complex and…

Quantum Physics · Physics 2014-03-04 K. F. Pál , T. Vértesi

There is a significant interest in testing quantum entanglement and Bell inequality violation in high-energy experiments. Since the analyses in high-energy experiments are performed with events statistically averaged over phase space, the…

High Energy Physics - Phenomenology · Physics 2024-06-11 Kun Cheng , Tao Han , Matthew Low

We address several problems concerning the geometry of the space of Hermitian operators on a finite-dimensional Hilbert space, in particular the geometry of the space of density states and canonical group actions on it. For quantum…

Mathematical Physics · Physics 2011-11-22 Janusz Grabowski , Marek Kus , Giuseppe Marmo

We investigate entanglement in two-qubit systems using a geometric representation based on the minimum of essential parameters. The latter is achieved by requiring subsystems with the same entropy, regardless of whether the state of the…

Quantum Physics · Physics 2024-12-24 Salvio Luna-Hernandez , Claudia Quintana , Oscar Rosas-Ortiz

We introduce a set of Bell inequalities for a three-qubit system. Each inequality within this set is violated by all generalized GHZ states. More entangled a generalized GHZ state is, more will be the violation. This establishes a relation…

Quantum Physics · Physics 2017-11-02 Arpan Das , Chandan Datta , Pankaj Agrawal

Any pure entangled state of two particles violates a Bell inequality for two-particle correlation functions (Gisin's theorem). We show that there exist pure entangled N>2 qubit states that do not violate any Bell inequality for N particle…

Quantum Physics · Physics 2009-11-07 Marek Zukowski , Caslav Brukner , Wieslaw Laskowski , Marcin Wiesniak

By calculating entanglement measures and quantum violation of Bell-type inequality, we reveal the relationship between entanglement measure and the amount of quantum violation for a family of four-qubit entangled states. It has been…

Quantum Physics · Physics 2017-06-07 Dong Ding , Yingqiu He , Fengli Yan , Ting Gao

In this paper, the Lorentz transformation of entangled Bell states seen by a moving observer is studied. The calculated Bell observable for 4 joint measurements turns out to give a universal value,…

Quantum Physics · Physics 2009-11-07 Doyeol Ahn , Hyuk-jae Lee , Young Hoon Moon , Sung Woo Hwang

We show that the rich structure of multipartite entanglement can be tested following a device-independent approach. Specifically we present Bell inequalities for distinguishing between different types of multipartite entanglement, without…

Quantum Physics · Physics 2015-05-30 Nicolas Brunner , James Sharam , Tamas Vertesi

Maximally entangled states should maximally violate the Bell inequality. In this paper, it is proved that all two-qubit states that maximally violate the Bell-Clauser-Horne-Shimony-Holt inequality are exactly Bell states and the states…

Quantum Physics · Physics 2009-11-10 Zeqian Chen

In this work we show that bipartite quantum states with local Hilbert space dimension n can violate a Bell inequality by a factor of order $\sqrt{n}$ (up to a logarithmic factor) when observables with n possible outcomes are used. A central…

Quantum Physics · Physics 2015-05-14 M. Junge , C. Palazuelos , D. Perez-Garcia , I. Villanueva , M. M. Wolf
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