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Related papers: Two-Setting Bell Inequalities for Many Qubits

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We give the complete list of 175 facet Bell inequalities for the case where Alice and Bob each choose their measurements from a set of four binary outcome measurements. For each inequality we compute the maximum quantum violation for…

Quantum Physics · Physics 2019-02-13 E. Zambrini Cruzeiro , N. Gisin

The worst violation of Bell's inequality for $n$ qbits is of size $2^{\frac{n-1}{2}}$ and it is obtained by a specific operator acting on a specific state. We show, to the contrary, that for a vast majority of Bell operators the worst…

Quantum Physics · Physics 2007-05-23 Itamar Pitowsky

Bell inequalities for number measurements are derived via the observation that the bits of the number indexing a number state are proper qubits. Violations of these inequalities are obtained from the output state of the nondegenerate…

Quantum Physics · Physics 2022-03-16 Jan-Åke Larsson

The number of steps required in order to maximize a Bell inequality for arbitrary number of qubits is shown to grow exponentially with either the number of steps and the number of parties involved. The proof that the optimization of such…

Quantum Physics · Physics 2015-03-03 J. Batle , C. H. Raymond Ooi

Joint quantum measurements of non-commuting observables are possible, if one accepts an increase in the measured variances. A necessary condition for a joint measurement to be possible is that a joint probability distribution exists for the…

Quantum Physics · Physics 2009-11-11 Wonmin Son , Erika Andersson , Stephem M. Barnett , M. S. Kim

I derive separability inequalities for Bell correlations of observables in arbitrary pure or mixed $N$ Qudit states in $D^N$-dimensional state space. I find states (a continuum of states if $D>3$) including maximally entangled states which…

Quantum Physics · Physics 2020-02-03 S. M. Roy

We report an exhaustive numerical analysis of violations of local realism by two qutrits in all possible pure entangled states. In Bell type experiments we allow any pairs of local unitary U(3) transformations to define the measurement…

Quantum Physics · Physics 2015-06-03 Jacek Gruca , Wieslaw Laskowski , Marek Zukowski

Multipartite nonlocality is of great fundamental interest and constitutes a useful resource for many quantum information protocols. However, demonstrating it in practice, by violating a Bell inequality, can be difficult. In particular,…

Quantum Physics · Physics 2015-06-25 Celal Furkan Senel , Thomas Lawson , Marc Kaplan , Damian Markham , Eleni Diamanti

Bell nonlocality -- the existence of quantum correlations that cannot be explained by classical means -- is certainly one of the most striking features of quantum mechanics. Its range of applications in device-independent protocols is…

Quantum Physics · Physics 2023-12-06 Rafael Santos , Debashis Saha , Flavio Baccari , Remigiusz Augusiak

Bell-inequality violation and entanglement, measured by Wootters' concurrence and negativity, of two qubits initially in Werner or Werner-like states coupled to thermal reservoirs are analyzed within the master equation approach. It is…

Quantum Physics · Physics 2009-08-03 Adam Miranowicz

For two qubits belonging to Alice and Bob, we derive an approach to setup the bound of Bell operator in the condition that Alice and Bob continue to perform local vertical measurements. For pure states we find that if the entanglement of…

Quantum Physics · Physics 2008-02-01 Yang Xiang , Shi-Jie Xiong

A proof of Bell's theorem using two maximally entangled states of two qubits is presented. It exhibits a similar logical structure to Hardy's argument of ``nonlocality without inequalities''. However, it works for 100% of the runs of a…

Quantum Physics · Physics 2009-11-06 Adan Cabello

We discuss a family of W-class states describing three-qubit systems. For such systems, we analyze the relations between the entanglement measures and the nonlocality parameter for a two-mode mixed state related to the two-qubit subsystem.…

Quantum Physics · Physics 2025-01-08 Joanna K. Kalaga , Wiesław Leoński , Jan Peřina

Which nonlocal correlations can be obtained, when a party has access to more than one subsystem? While traditionally nonlocality deals with spacelike separated parties, this question becomes important with quantum technologies that connect…

Quantum Physics · Physics 2023-09-04 Moisés Bermejo Morán , Alejandro Pozas-Kerstjens , Felix Huber

A Greenberger Horne Zeilinger (GHZ) entangled state with a phase is crucial for realizing desired multipartite quantum states for practical applications. Here, we report violations of the general Bell inequality (GBI) introduced in [1]…

Quantum Physics · Physics 2023-03-16 Jiho Park , Junghee Ryu , Heonoh Kim , Han Seb Moon

Lorentz transformation of three-qubit Greenberger-Horne-Zeilinger (GHZ) state is studied. Also we obtain the relativistic spin joint measurement for the transformed state. Using these results it is shown that Bell's inequality is maximally…

Quantum Physics · Physics 2015-06-03 Shahpoor Moradi

It remains an open question whether every pure multipartite state that is genuinely entangled is also genuinely nonlocal. Recently, a new general construction of Bell inequalities allowing the detection of genuine multipartite nonlocality…

Quantum Physics · Physics 2024-09-23 Ignacy Stachura , Owidiusz Makuta , Remigiusz Augusiak

We strengthen the bound on the correlations of two spin-1/2 particles (qubits) in separable (non-entangled) states for locally orthogonal spin directions by much tighter bounds than the well-known Bell inequality. This provides a sharper…

Quantum Physics · Physics 2008-02-22 J. Uffink , M. Seevinck

We introduce a geometric framework for studying Bell nonlocality in Hilbert space, where, for a given quantum state, nonlocality is quantified by the distance between the state and the set of local states. This approach applies to any Bell…

We put forward complementary relations of entanglement, coherence, steering inequality violation, and Bell nonlocality for arbitrary three-qubit states. We show that two families of genuinely entangled three-qubit pure states with single…

Quantum Physics · Physics 2023-05-24 Dong-Dong Dong , Xue-Ke Song , Xiao-Gang Fan , Liu Ye , Dong Wang
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