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Related papers: An anomaly of non-locality

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We discuss the relation between entanglement and nonlocality in the hidden nonlocality scenario. Hidden nonlocality signifies nonlocality that can be activated by applying local filters to a particular state that admits a local…

Quantum Physics · Physics 2020-02-12 Lucas Tendick , Hermann Kampermann , Dagmar Bruß

Hardy's argument constitutes an elegantly logical test for identifying nonlocal features of multipartite correlations. In this paper, we investigate Hardy's nonlocal behavior within a broad class of operational theories, including the qubit…

Bell's theorem, stating that quantum predictions are incompatible with a local hidden variable description, is a cornerstone of quantum theory and at the center of many quantum information processing protocols. Over the years, different…

Quantum Physics · Physics 2020-05-27 I. S. Eliëns , S. G. A. Brito , R. Chaves

We consider a general version of the phenomenon of more nonlocality with less entanglement, within the framework of the unambiguous (i.e., conclusive) quantum state discrimination problem under local quantum operations and classical…

Quantum Physics · Physics 2022-03-25 Saronath Halder , Ujjwal Sen

Apart from the Bell nonlocality, which deals with the correlations generated from the local input-output statistics, quantum theory exhibits another kind of nonlocality that involves the indistiguishability of the locally preparable set of…

Quantum metrology allows for a huge boost in the precision of parameters estimation. However, it seems to be extremely sensitive on the noise. Bound entangled states are states with large amount of noise what makes them unusable for almost…

Quantum Physics · Physics 2015-12-09 L. Czekaj , A. Przysiezna , M. Horodecki , P. Horodecki

Starting from several copies of bipartite noisy entangled states, we design a global and optimal local measurement-based protocol in one- and two-dimensional lattices by which any two or more prefix sites can be connected via entanglement.…

Quantum Physics · Physics 2021-01-04 Ratul Banerjee , Srijon Ghosh , Shiladitya Mal , Aditi Sen De

Hardy's non-locality theorem for multiple two-level systems is explored in the context of generalized nonlocal theory. We find nonlocal but non-signaling probabilities, providing Hardy's nonlocal argument, which are higher than those in…

Quantum Physics · Physics 2011-11-01 Sujit K. Choudhary , Sibasish Ghosh , Guruprasad Kar , Samir Kunkri , Ramij Rahaman , Anirban Roy

We have studied the possibility of post-quantum theories more nonlocal than the (standard) quantum theory using the modification of the quantum probability rule under the no-signaling condition. For this purpose we have considered the…

Quantum Physics · Physics 2012-08-15 Yeong Deok Han , Taeseung Choi

Quantum entanglement and nonlocality are inextricably linked. However, while entanglement is necessary for nonlocality, it is not always sufficient in the standard Bell scenario. We derive sufficient conditions for entanglement to give rise…

Quantum Physics · Physics 2021-02-22 Patricia Contreras-Tejada , Carlos Palazuelos , Julio I. de Vicente

Entanglement swapping is a process by which two initially independent quantum systems can become entangled and generate nonlocal correlations. To characterize such correlations, we compare them to those predicted by bilocal models, where…

Quantum Physics · Physics 2012-03-23 Cyril Branciard , Denis Rosset , Nicolas Gisin , Stefano Pironio

Entanglement is a special feature of the quantum world that reflects the existence of subtle, often non-local, correlations between local degrees of freedom. In topological theories such non-local correlations can be given a very intuitive…

High Energy Physics - Theory · Physics 2020-01-31 D. Melnikov , A. Mironov , S. Mironov , A. Morozov , An. Morozov

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

We introduce a new aspect of nonlocality which arises when the task of quantum states distinguishability is considered under local operations and shared entanglement in the absence of classical communication. We find the optimal amount of…

Quantum Physics · Physics 2016-03-24 Berry Groisman , Sergii Strelchuk

Entanglement is a central and subtle feature of quantum theory, whose structure and operational behavior can change dramatically when additional physical constraints, such as symmetries or superselection rules, are imposed. Such constraints…

Quantum Physics · Physics 2026-02-19 Roberto D. Baldijão , Marco Erba , David Schmid , John H. Selby , Ana Belén Sainz

Most working scientists hold fast to the concept of 'realism' - a viewpoint according to which an external reality exists independent of observation. But quantum physics has shattered some of our cornerstone beliefs. According to Bell's…

Quantum correlations, like entanglement, represent the characteristic trait of quantum mechanics, and pose essential issues and challenges to the interpretation of this pillar of modern physics. Although quantum correlations are largely…

Non-locality without inequality is an elegant argument introduced by L. Hardy for two qubit systems, and later generalised to $n$ qubits, to establish contradiction of quantum theory with local realism. Interestingly, for $n=2$ this…

Quantum Physics · Physics 2015-05-19 Sibasish Ghosh , Shasanka Mohan Roy

We provide an explicit example of a Bell inequality with 3 settings and 2 outcomes per site for which the largest violation is not obtained by the maximally entangled state, even if its dimension is allowed to be arbitrarily large. This…

Quantum Physics · Physics 2013-05-29 Thomas Vidick , Stephanie Wehner

Bell's theorem proves that quantum theory is inconsistent with local physical models. It has propelled research in the foundations of quantum theory and quantum information science. As a fundamental feature of quantum theory, it impacts…

Quantum Physics · Physics 2022-04-06 Armin Tavakoli , Alejandro Pozas-Kerstjens , Ming-Xing Luo , Marc-Olivier Renou