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Related papers: Optimization of Bell's Inequality Violation For Co…

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When a collection of distant observers share an entangled quantum state, the statistical correlations among their measurements may violate a many-body Bell inequality, demonstrating a non-local behavior. Focusing on the Ising model in a…

Strongly Correlated Electrons · Physics 2019-10-25 Angelo Piga , Albert Aloy , Maciej Lewenstein , Irénée Frérot

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

A set of Bell inequalities classifying the quantum entanglement of four-qubit states is presented. These inequalities involve only two measurement settings per observer and can characterize fully separable, bi-separable and tri-separable…

Quantum Physics · Physics 2013-07-26 Hui Zhao , Xing-Hua Zhang , Shao-Ming Fei , Zhi-Xi Wang

In order to understand the characteristics of quantum entanglement of massive particles under Lorentz boost, we first introduce a relevant relativistic spin observable, and evaluate its expectation values for the Bell states under Lorentz…

Quantum Physics · Physics 2016-09-08 Daeho Lee , Ee Chang-Young

Bell inequalities were meant to test quantum mechanics vs local hidden variable models, but can also be used to verify entanglement. For entanglement verification purposes one assumes the validity of quantum mechanics as well as quantum…

Quantum Physics · Physics 2015-05-13 Pavel Lougovski , S. J. van Enk

This paper solves the open problem of characterizing the performance of quantum illumination (QI) with discrete variable states. By devising a novel quantum measurement approach along with meticulous analysis, our investigation demonstrates…

Quantum Physics · Physics 2024-07-12 Armanpreet Pannu , Amr S. Helmy , Hesham El Gamal

We show that for two-qubit chained Bell inequalities with an arbitrary number of measurement settings, nonlocality and entanglement are not only different properties but are inversely related. Specifically, we analytically prove that in…

Quantum Physics · Physics 2014-01-08 G. Vallone , G. Lima , E. S. Gómez , G. Cañas , J. -A. Larsson , P. Mataloni , A. Cabello

The states generated by the two-spin generalization of the two-axis countertwisting Hamiltonian are examined. We analyze the behavior at both short and long timescales, by calculating various quantities such as squeezing, spin expectation…

In this paper we introduce a simple and natural bipartite Bell scenario, by considering the correlations between two parties defined by general measurements in one party and dichotomic ones in the other. We show that unbounded Bell…

Quantum Physics · Physics 2015-11-18 C. Palazuelos , Z. Yin

We identify a class of two-mode squeezed states which are parametrized by an angular variable ${0\le\theta<2\pi}$ and a squeezing parameter $r$. We show that, for a large squeezing value, these states are either (almost) maximally entangled…

Quantum Physics · Physics 2015-05-18 Amir Kalev , Faqir C. Khanna , Michael Revzen

This paper concerns parameterized convex infinite (or semi-infinite) inequality systems whose decision variables run over general infinite-dimensional Banach (resp. finite-dimensional) spaces and that are indexed by an arbitrary fixed set T…

Optimization and Control · Mathematics 2011-02-07 M. J. CÁnovas , M. A. LÓpez , B. S. Mordukhovich , J. Parra

Temporal Bell inequalities, or Leggett-Garg Inequalities (LGI), are studied for continuous-variable systems placed in a squeezed state. The importance of those systems lies in their broad applicability which allows the description of many…

Quantum Physics · Physics 2021-07-19 Jerome Martin , Vincent Vennin

This paper is concerned with the maximum principle of stochastic optimal control problems, where the coefficients of the state equation and the cost functional are uncertain, and the system is generally under Markovian regime switching.…

Optimization and Control · Mathematics 2025-04-15 Tao Hao , Jiaqiang Wen , Jie Xiong

We study Bell's inequality using the Bell states constructed from four component Dirac spinors. Spin operator is related to the Pauli-Lubanski pseudo vector which is relativistic invariant operator. By using Lorentz transformation, in both…

Quantum Physics · Physics 2015-06-03 Shahpoor Moradi

Quantum correlations between spatially separated parts of a $d$-dimensional bipartite system ($d\geq 2$) have no classical analog. Such correlations, also called entanglements, are not only conceptually important, but also have a profound…

Previous work on Bell's inequality realised in the laboratory has used entangled photons. Here we describe how entangled atoms can violate Bell's inequality, and how these violations can be measured with a very high detection efficiency. We…

Quantum Physics · Physics 2009-11-06 Almut Beige , William J. Munro , Peter L. Knight

Solid experimental evidence has now been obtained that confirms the violation of Bell's inequality in tests of maximally entangled qubit pairs. This violation is widely interpreted as definitive proof of the impossibility of describing…

Quantum Physics · Physics 2025-10-20 David H. Oaknin

We consider bipartite quantum systems characterized by a continuous angular variable \theta \in [-\pi, \pi[, representing, for instance, the position of a particle on a circle. We show how to reveal non-locality on this type of system using…

Quantum Physics · Physics 2012-11-26 Carolina V. S. Borges , Perola Milman , Arne Keller

We discuss quantum entanglement and violation of Bell inequalities in the $H\rightarrow ZZ$ decay, in particular when the two $Z-$bosons decay into light leptons. Although such process implies an important suppression of the statistics,…

High Energy Physics - Phenomenology · Physics 2023-02-01 J. A. Aguilar-Saavedra , A. Bernal , J. A. Casas , J. M. Moreno

Choosing four entangled stets to form an orthogonal and complete basis for a two-particle system, we argue that a local hidden variable model should give the probability of each entangled state if the two-particle system is described by a…

Quantum Physics · Physics 2009-11-07 Xiao-Hua Wu , HongShi Zong , Hou-Rong Pang , Fan Wang