English
Related papers

Related papers: Proofs of nonlocality without inequalities revisit…

200 papers

While Bell nonlocality of a bipartite system is counter-intuitive, multipartite nonlocality in our many-body world turns out to be even more so. Recent theoretical study reveals in a theory-agnostic manner that genuine multipartite nonlocal…

Quantum Physics · Physics 2022-10-19 Ya-Li Mao , Zheng-Da Li , Sixia Yu , Jingyun Fan

Two approaches to extend Hardy's proof of nonlocality without inequalities to maximally entangled states of bipartite two-level systems are shown to fail. On one hand, it is shown that Wu and co-workers' proof [Phys. Rev. A 53, R1927…

Quantum Physics · Physics 2009-10-31 Adan Cabello

As a striking manifestation of quantum entanglement, nonlocality has long played a pivotal role in shaping our understanding of the quantum world. When considering a Bell test involving three parties, we may even find a remarkable situation…

Quantum Physics · Physics 2026-04-10 Kai-Siang Chen , Gelo Noel M. Tabia , Chung-Yun Hsieh , Yu-Chun Yin , Yeong-Cherng Liang

We consider the local unitary equivalence of a class of quantum states in bipartite case and multipartite case. The necessary and sufficient condition is presented. As special cases, the local unitary equivalent classes of isotropic state…

Quantum Physics · Physics 2016-09-21 Tinggui Zhang , Bobo Hua , Ming Li , Ming-Jing Zhao , Hong Yang

Bell inequalities define experimentally observable quantities to detect non-locality. In general, they involve correlation functions of all the parties. Unfortunately, these measurements are hard to implement for systems consisting of many…

Quantum Physics · Physics 2014-07-14 J. Tura , R. Augusiak , A. B. Sainz , T. Vértesi , M. Lewenstein , A. Acín

In this paper we study the non-local properties of permutation symmetric states of n-qubits. We extend the bipartite Hardy paradox and the associated CH-inequality to n-party permutation symmetric states to show that all symmetric states…

Quantum Physics · Physics 2012-05-28 Zizhu Wang , Damian Markham

The nonlocal properties for a kind of generic N-dimensional bipartite quantum systems are investigated. A complete set of invariants under local unitary transformations is presented. It is shown that two generic density matrices are locally…

Quantum Physics · Physics 2009-11-10 Sergio Albeverio , Shao-Ming Fei , Preeti Parashar , Wen-Li Yang

This is to reply to Cereceda's comment on "Quantum nonlocality for a three-particle nonmaximally entangled state without inequaltiy"

Quantum Physics · Physics 2007-05-23 Shi-Biao Zheng

Based on the relative entropy, we give a unified characterization of quantum correlations for nonlocality, steerability, discord and entanglement for any bipartite quantum states. For two-qubit states we show that the quantities obtained…

Quantum Physics · Physics 2017-04-14 Tinggui Zhang , Hong Yang , Xianqing Li-Jost , Shao-Ming Fei

The Bell and the Clauser-Horne-Shimony-Holt inequalities are shown to hold for both the cases of complex and real analytic nonlocality in the setting parameters of Einstein-Podolsky-Rosen-Bohm experiments for spin 1/2 particles and photons,…

Quantum Physics · Physics 2009-11-10 M. Socolovsky

We experimentally demonstrate the superior discrimination of separated, unentangled two-qubit correlated states using nonlocal measurements, when compared with measurements based on local operations and classical communications. When…

Quantum Physics · Physics 2008-11-26 G. J. Pryde , J. L. O'Brien , A. G. White , Stephen D. Bartlett

We provide necessary and sufficient conditions for the partial transposition of bipartite harmonic quantum states to be nonnegative. The conditions are formulated as an infinite series of inequalities for the moments of the state under…

Quantum Physics · Physics 2009-11-11 E. Shchukin , W. Vogel

We generalize the Greenberger-Horne-Zeilinger nonlocality without inequalities argument to cover the case of arbitrary mixed statistical operators associated to three-qubits quantum systems. More precisely, we determine the radius of a ball…

Quantum Physics · Physics 2009-11-13 GianCarlo Ghirardi , Luca Marinatto

We present a general method to characterize the quantum correlations obtained after local measurements on multipartite systems. Sufficient conditions for a quantum system to be fully-nonlocal according to a given partition, as well as being…

Quantum Physics · Physics 2015-05-14 Mafalda L. Almeida , Daniel Cavalcanti , Valerio Scarani , Antonio Acin

The Clauser-Horne-Shimony and Holt inequality applies when measurements with binary outcomes are performed on physical systems under the assumption of local realism. Testing such inequalities in the quantum realm usually involves either…

Quantum Physics · Physics 2015-04-28 A. Ketterer , A. Keller , T. Coudreau , P. Milman

We study the invariants of arbitrary dimensional multipartite quantum states under local unitary transformations. For multipartite pure states, we give a set of invariants in terms of singular values of coefficient matrices. For…

Quantum Physics · Physics 2015-09-04 Ting-Gui Zhang , Ming-Jing Zhao , Xianqing Li-Jost , Shao-Ming Fei

We show that some tripartite quantum correlations are inexplicable by any causal theory involving bipartite nonclassical common causes and unlimited shared randomness. This constitutes a device-independent proof that Nature's nonlocality is…

Quantum Physics · Physics 2022-07-20 Xavier Coiteux-Roy , Elie Wolfe , Marc-Olivier Renou

A set of orthogonal product states of a composite Hilbert space is genuinely nonlocal if the states are locally indistinguishable across any bipartition. In this work, we construct a minimal set of party asymmetry genuine nonlocal set in…

Quantum Physics · Physics 2025-08-21 Atanu Bhunia , Indrani Chattopadhyay , Debasis Sarkar

In recent years, the use of information principles to understand quantum correlations has been very successful. Unfortunately, all principles considered so far have a bipartite formulation, but intrinsically multipartite principles, yet to…

Quantum Physics · Physics 2014-03-03 T. Fritz , A. B. Sainz , R. Augusiak , J. B. Brask , R. Chaves , A. Leverrier , A. Acín

Quantum nonlocality is usually associated with entangled states by their violations of Bell-type inequalities. However, even unentangled systems, whose parts may have been prepared separately, can show nonlocal properties. In particular, a…

Quantum Physics · Physics 2019-02-06 Saronath Halder , Manik Banik , Sristy Agrawal , Somshubhro Bandyopadhyay