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Related papers: Super-activation of quantum non-locality

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We introduce a general method which converts, in a unified way, any form of quantum contextuality, including any form of state-dependent contextuality, into a quantum violation of a bipartite Bell inequality. As an example, we apply the…

Quantum Physics · Physics 2021-08-12 Adán 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

By combining two objects with no quantum effect one can get an object with quantum effect. Such a phenomenon, often referred to as activation has been analyzed for the notion of steering nonlocality. Activation of steering nonlocality is…

Quantum Physics · Physics 2023-03-22 Kaushiki Mukherjee , Biswajit Paul , Soma Mandal

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

Bell nonlocality provides a robust scalable route to the efficient certification of quantum states. Here, we introduce a general framework for constructing Bell inequalities tailored to the $\mathbb{Z}_d$ toric code for odd prime local…

Quantum Physics · Physics 2025-12-02 Eloïc Vallée , Owidiusz Makuta , Patrick Emonts , Rhine Samajdar , Jordi Tura

Contrary to Bell scenario, quantum nonlocality can be exploited even when all the parties do not have freedom to select inputs randomly. Such manifestation of nonlocality is possible in networks involving independent sources. One can…

Quantum Physics · Physics 2020-04-20 Kaushiki Mukherjee , Biswajit Paul , Arup Roy

We show that arbitrary functions of continuous variables, e.g. position and momentum, can be used to generate tests that distinguish quantum theory from local hidden variable theories. By optimising these functions, we obtain more robust…

Quantum Physics · Physics 2009-11-16 Q. Y. He , E. G. Cavalcanti , M. D. Reid , P. D. Drummond

Bell's theorem states that, to simulate the correlations created by measurement on pure entangled quantum states, shared randomness is not enough: some "non-local" resources are required. It has been demonstrated recently that all…

Quantum Physics · Physics 2009-11-10 Nicolas Brunner , Nicolas Gisin , Valerio Scarani

In most Bell tests, the measurement settings are specially chosen so that the maximal quantum violations of the Bell inequalities can be detected, or at least, the violations are strong enough to be observed. Such choices can usually…

Quantum Physics · Physics 2022-10-21 Weidong Tang

Quantum nonlocality can be revealed "via local contextuality" in qudit-qudit entangled systems with $d > 2$, that is, through the violation of inequalities containing Alice-Bob correlations that admit a local description, and Alice-Alice…

Quantum Physics · Physics 2016-05-03 Debashis Saha , Adán Cabello , Sujit K. Choudhary , Marcin Pawłowski

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

The standard Bell inequality experiments test for violation of local realism by repeatedly making local measurements on individual copies of an entangled quantum state. Here we investigate the possibility of increasing the violation of a…

Quantum Physics · Physics 2007-05-23 Yeong-Cherng Liang , Andrew C. Doherty

It is well known that measurements performed on spatially separated entangled quantum systems can give rise to correlations that are non-local, in the sense that a Bell inequality is violated. They cannot, however, be used for super-luminal…

Quantum Physics · Physics 2007-10-22 Jonathan Barrett , Noah Linden , Serge Massar , Stefano Pironio , Sandu Popescu , David Roberts

Bell type inequalities are used to test local realism against quantum theory.In this paper, we consider a two party system with two settings and two possible outcomes on each side, and derive equalities in local theories which are violated…

Quantum Physics · Physics 2007-05-23 Hossein Movahhedian

Bell inequalities reveal the fundamentally nonlocal character of quantum mechanics. In this regard, one of the interesting problems is to explore all possible Bell inequalities that demonstrate a gap between local and nonlocal quantum…

Quantum Physics · Physics 2026-02-10 Palash Pandya , Shubhayan Sarkar , Remigiusz Augusiak

The experimental results that test Bell's inequality have found strong evidence suggesting that there are nonlocal aspects in nature. Evidently, these nonlocal effects, which concern spacelike separated regions, create an enormous tension…

General Relativity and Quantum Cosmology · Physics 2022-12-07 Yuri Bonder , Johas D. Morales

The results of local measurements on some composite quantum systems cannot be reproduced classically. This impossibility, known as quantum nonlocality, represents a milestone in the foundations of quantum theory. Quantum nonlocality is also…

Quantum Physics · Physics 2015-05-20 D. Cavalcanti , M. L. Almeida , V. Scarani , A. Acin

By assuming a deterministic evolution of quantum systems and taking realism into account, we carefully build a hidden variable theory for Quantum Mechanics based on the notion of ontological states proposed by 't Hooft. We view these…

Quantum Physics · Physics 2017-12-04 Natalia Sánchez-Kuntz , Eduardo Nahmad-Achar

Quantum nonlocality, one of the most important features of quantum mechanics, is normally connected in experiments with the violation of Bell-Clauser-Horne (Bell-CH) inequalities. We propose effective methods for the rearrangement and…

Quantum Physics · Physics 2021-06-08 Chen Qian , Yang-Guang Yang , Cong-Feng Qiao , Qun Wang

We propose a tomographic approach to study quantum nonlocality in continuous variable quantum systems. On one hand we derive a Bell-like inequality for measured tomograms. On the other hand, we introduce pseudospin operators whose…

Quantum Physics · Physics 2009-11-10 Stefano Mancini , Vladimir I. Man'ko , Evgeny V. Shchukin , Paolo Tombesi