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Related papers: Bell's theorem for general N-qubit states

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The logical foundations of Bell's inequality are reexamined. We argue that the form of the reality condition that underpins Bell's inequality comes from the requirement of solving the quantum measurement problem. Hence any violation of…

Quantum Physics · Physics 2008-02-19 John V. Corbett , Dipankar Home

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

We introduce a hierarchy of conditions necessarily satisfied by any distribution P(ab) representing the probabilities for two separate observers to obtain outcomes a and b when making local measurements on a shared quantum state. Each…

Quantum Physics · Physics 2008-03-30 Miguel Navascues , Stefano Pironio , Antonio Acin

Bell's theorem is a fundamental theorem in physics concerning the incompatibility between some correlations predicted by quantum theory and a large class of physical theories. In this paper, we introduce the hypothesis of accountability,…

Quantum Physics · Physics 2014-11-27 Nicola Vona , Yeong-Cherng Liang

Based on a geometrical argument introduced by Zukowski, a new multisetting Bell inequality is derived, for the scenario in which many parties make measurements on two-level systems. This generalizes and unifies some previous results.…

Quantum Physics · Physics 2009-11-13 Koji Nagata , Wieslaw Laskowski , Tomasz Paterek

We derive tight quadratic inequalities for all kinds of hybrid separable-inseparable $n$-particle density operators on an arbitrary dimensional space. This methodology enables us to truly derive a tight quadratic inequality as tests for…

Quantum Physics · Physics 2009-11-07 Koji Nagata , Masato Koashi , Nobuyuki Imoto

Quantum theory allows for correlations between the outcomes of distant measurements that are inconsistent with any locally causal theory, as demonstrated by the violation of a Bell inequality. Typical demonstrations of these correlations…

Quantum Physics · Physics 2012-02-08 Joel J. Wallman , Stephen D. Bartlett

For a system composed of two particles Bell's theorem asserts that averages of physical quantities determined from local variables must conform to a family of inequalities. In this work we show that a classical model containing a local…

Quantum Physics · Physics 2008-06-22 A. Matzkin

We established a physically utilizable Bell inequality based on the Peres-Horodecki criterion. The new quadratic probabilistic Bell inequality naturally provides us a necessary and sufficient way to test all entangled two-qubit or…

Quantum Physics · Physics 2007-06-22 Jing-Ling Chen , Ming-Guang Hu

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

The Bell inequality is thought to be a common constraint shared by all models of local hidden variables that aim to describe the entangled states of two qubits. Since the inequality is violated by the quantum mechanical description of these…

General Physics · Physics 2020-08-05 David H. Oaknin

Derivation of the full set of Bell inequalities involving correlation functions, for two parties, with binary observables, and N possible local settings is not as easy as it seemed. The proof of v1 is wrong. Additionaly one can find a…

Quantum Physics · Physics 2007-06-13 Piotr Badziag , Marek Zukowski

We analyze and compare the mathematical formulations of the criterion for separability for bipartite density matrices and the Bell inequalities. We show that a violation of a Bell inequality can formally be expressed as a witness for…

Quantum Physics · Physics 2009-10-31 Barbara M. Terhal

Bell's theorem is a statement by which averages obtained from specific types of statistical distributions must conform to a family of inequalities. These models, in accordance with the EPR argument, provide for the simultaneous existence of…

Quantum Physics · Physics 2009-04-13 A. Matzkin

Bell's theorem is typically understood as the proof that quantum theory is incompatible with local-hidden-variable models. More generally, we can see the violation of a Bell inequality as witnessing the impossibility of explaining quantum…

For linear combinations of quantum product averages in an arbitrary bipartite state, we derive new quantum Bell-form and CHSH-form inequalities with the right-hand sides expressed in terms of a bipartite state. This allows us to specify in…

Quantum Physics · Physics 2011-01-04 Elena R. Loubenets

The connection between quantum optical nonclassicality and the violation of Bell's inequalities is explored. Bell type inequalities for the electromagnetic field are formulated for general states(arbitrary number or photons, pure or mixed)…

Quantum Physics · Physics 2007-05-23 Arvind , N. Mukunda

Consider a scenario where $N$ separated quantum systems are measured, each with one among two possible dichotomic observables. Assume that the $N$ events corresponding to the choice and performance of the measurement in each site are…

Quantum Physics · Physics 2007-05-23 Ll. Masanes

We present a set of Bell inequalities which are sufficient and necessary for separability of general pure multipartite quantum states in arbitrary dimensions. The relations between Bell inequalities and distillability are also studied. We…

Quantum Physics · Physics 2010-06-18 Ming Li , Shao-Ming Fei

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