English
Related papers

Related papers: Test of Genuine Multipartite Nonlocality

200 papers

We consider a bipartite scenario where two parties hold ensembles of $1/2$-spins which can only be measured collectively. We give numerical arguments supporting the conjecture that in this scenario no Bell inequality can be violated for…

Quantum Physics · Physics 2019-10-30 Enky Oudot , Jean-Daniel Bancal , Pavel Sekatski , Nicolas Sangouard

Bell showed 50 years ago that quantum theory is nonlocal via his celebrated inequalities, turning the issue of quantum nonlocality from a matter of taste into a matter of test. Years later, Hardy proposed a test for nonlocality without…

Quantum Physics · Physics 2014-10-13 Sixia Yu

In a Bell experiment, it is natural to seek a causal account of correlations wherein only a common cause acts on the outcomes. For this causal structure, Bell inequality violations can be explained only if causal dependencies are modelled…

Quantum resources play crucial roles for displaying superiority in many quantum communication and computation tasks. To reveal the intrinsic relations hidden in these quantum resources, many efforts have been made in recent years. In this…

Quantum Physics · Physics 2019-03-27 Wen-Yang Sun , Dong Wang , Bao-Long Fang , Zhi-Yong Ding , Huan Yang , Fei Ming , Liu Ye

We study the nonlocal properties of two-qubit maximally-entangled and N-qubit Greenberger-Horne-Zeilinger states under local decoherence. We show that the (non)resilience of entanglement under local depolarization or dephasing is not…

Quantum Physics · Physics 2015-06-04 Rafael Chaves , Daniel Cavalcanti , Leandro Aolita , Antonio Acín

Energy-time entangled biphoton source plays a great role in quantum communication, quantum metrology and quantum cryptography due to its strong temporal correlation and capability of nonlocal dispersion cancellation. As a quantum effect,…

Quantum Physics · Physics 2019-11-06 Baihong Li , Feiyan Hou , Runai Quan , Ruifang Dong , Lixing You , Hao Li , Xiao Xiang , Tao Liu , Shougang Zhang

Wang et al. [Science Advances, 1 Aug 2025 Vol 11, Issue 31] recently reported an experiment that they interpret as demonstrating a violation of Bell's inequality using unentangled photons. Such a claim is highly controversial, since it is…

Quantum Physics · Physics 2025-09-04 Antoni Wójcik , Jan Wójcik

Facet inequalities play an important role in detecting the nonlocality of a quantum state. The number of such inequalities depends on the Bell test scenario. With the increase in the number of parties, measurement outcomes, or/and the…

Quantum Physics · Physics 2023-03-20 Arpan Das , Chandan Datta , Pankaj Agrawal

Quantum nonlocality of several four-qubit states is investigated by constructing a new Bell inequality. These include the Greenberger-Zeilinger-Horne (GHZ) state, W state, cluster state, and the state $|\chi>$ that has been recently…

Quantum Physics · Physics 2013-05-29 Chunfeng Wu , Ye Yeo , L. C. Kwek , C. H. Oh

We study the nonlocality of arbitrary dimensional bipartite quantum states. By computing the maximal violation of a set of multi-setting Bell inequalities, an analytical and computable lower bound has been derived for general two-qubit…

Quantum Physics · Physics 2015-09-04 Ming Li , Tinggui Zhang , Bobo Hua , Shao-Ming Fei , Xianqing Li-Jost

Quantum nonlocality is arguably among the most counter-intuitive phenomena predicted by quantum theory. In recent years, the development of an abstract theory of nonlocality has brought a much deeper understanding of the subject. In…

Based on the optimal quantum violation of suitable Bell's inequality, the device-independent self-testing of state and observables has been reported. It is well-studied that locally commuting or compatible observables cannot be used to…

Quantum Physics · Physics 2023-11-09 Sneha Munshi , A. K. Pan

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…

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

It is argued that Bell's nonlocality is a particular case of nonlocality at detection, which appears already in single-particle interference experiments. The unity of nonlocality and local causality is crucial to provide a consistent…

Quantum Physics · Physics 2010-09-06 Antoine Suarez

Nonlocality as a fundamental aspect of quantum mechanics is witnessed by violation of Bell inequality or its variants, for which all relevant studies assume some correlations exhibited by local realistic theories. The strategy of Bell's…

Quantum Physics · Physics 2020-12-04 Boya Xie , Sheng Feng

This work investigates network nonlocality sharing for a broad class of bipartite Bell inequalities in a generalized star network with an $(n,m,k)$ configuration, comprising $n$ independent branches, $m$ sequential Alices per branch, and…

Quantum Physics · Physics 2026-01-29 Hao-Miao Jiang , Xiang-Jiang Chen , Liu-Jun Wang , Qing Chen

Experiments showing the violation of Bell inequalities have formed our belief that the world at its smallest is genuinely non-local. While many non-locality experiments use the first quantised picture, the physics of fields of…

Quantum Physics · Physics 2013-05-29 Libby Heaney , Janet Anders

The widespread claim that violations of Bell inequalities establish the nonlocality of nature is critically reexamined. It is argued that this conclusion is not logically compelled by either the Einstein-Podolsky-Rosen (EPR) argument or…

Quantum Physics · Physics 2026-05-05 Partha Ghose

Nonlocal correlations as revealed by the violations to Bell inequalities are incompatible with local models without any nonlocal correlations. However some tripartite entangled states, e.g., symmetric pure states, exhibit a stronger…

Quantum Physics · Physics 2013-06-25 Sixia Yu , C. H. Oh