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Related papers: Quantum Counterfactuals and Locality

200 papers

The framework of locally covariant quantum field theory, an axiomatic approach to quantum field theory in curved spacetime, is reviewed. As a specific focus, the connection between spin and statistics is examined in this context. A new…

General Relativity and Quantum Cosmology · Physics 2016-05-25 Christopher J. Fewster

This paper points out the importance of the assumption of locality of physical interactions, and the concomitant necessity of propagation of an entity (in this case, off-shell quanta - virtual gravitons) between two non-relativistic test…

Quantum Physics · Physics 2020-05-22 Ryan J. Marshman , Anupam Mazumdar , Sougato Bose

We consider a quantum system subject to superselection rules, for which certain restrictions apply to the quantum operations that can be implemented. It is shown how the notion of quantum-nonlocality has to be redefined in the presence of…

Quantum Physics · Physics 2009-11-10 F. Verstraete , J. I. Cirac

Hidden-variable theories effectively solve the measurement problem. However, a serious issue of this route towards a realistic completion of quantum theory is raised by Bell's proof that the resulting theories are nonlocal. A possible…

Quantum Physics · Physics 2025-08-26 Alberto Montina , Stefan Wolf

Nonlocality is a distinctive feature of quantum theory, which has been extensively studied for decades. It is found that the uncertainty principle determines the nonlocality of quantum mechanics. Here we show that various degrees of…

Quantum Physics · Physics 2023-06-14 Ma-Cheng Yang , Jun-Li Li , Cong-Feng Qiao

Quantum codewords are highly entangled combinations of two-state systems. The standard assumptions of local realism lead to logical contradictions similar to those found by Bell, Kochen and Specker, Greenberger, Horne and Zeilinger, and…

Quantum Physics · Physics 2008-12-18 David P. DiVincenzo , Asher Peres

There are two powerful arguments against the possibility of extending quantum mechanics, the violation of Bell inequalities and the Kochen-Specker theorem, but the connection between the two remains confused. Following the distinctive…

Quantum Physics · Physics 2025-01-08 Jianqi Sheng , Dongkai Zhang , Lixiang Chen

We experimentally show that nonlocality can be produced from single-particle contextuality by using two-particle correlations which do not violate any Bell inequality by themselves. This demonstrates that nonlocality can come from an {\em a…

Quantum contextuality, where measurement outcomes depend on the measurement context, implies a failure of classical realism in quantum systems. As recently shown, the transition between measurement contexts can be mapped onto the path that…

Quantum Physics · Physics 2026-01-22 Yuki Sagawa , Jonte R. Hance , Holger F. Hofmann , Takafumi Ono

Everyday experience supports the existence of physical properties independent of observation in strong contrast to the predictions of quantum theory. In particular, existence of physical properties that are independent of the measurement…

Quantum Physics · Physics 2016-03-09 Beatrix C. Hiesmayr , Jan-Å ke Larsson

We provide a cohomological framework for contextuality of quantum mechanics that is suited to describing contextuality as a resource in measurement-based quantum computation. This framework applies to the parity proofs first discussed by…

Quantum Physics · Physics 2017-10-18 Cihan Okay , Sam Roberts , Stephen D. Bartlett , Robert Raussendorf

The nonlocal action of a measurement performed on a quantum entangled particle can determine the quantum state of a distant entangled particle instantly. Since the relativistic simultaneity of events is frame dependent therefore, a…

Quantum Physics · Physics 2022-10-10 Mandip Singh

Counterfactuals in quantum theory are briefly reviewed and it is argued that they are very different from counterfactuals considered in the general philosophical literature. The issue of time symmetry of quantum counterfactuals is…

Quantum Physics · Physics 2007-05-23 L. Vaidman

The Quantum-Bayesian interpretation of quantum theory claims to eliminate the question of quantum nonlocality. This claim is not justified, because the question of non-locality does not arise due to any interpretation of quantum theory, but…

Quantum Physics · Physics 2016-07-01 Gerold Gründler

Hardy's argument constitutes an elegant proof of quantum nonlocality. In this work, we report an exotic application of Hardy's nonlocal correlations in two-party communication setup. We come up with a task, wherein a positive payoff can be…

In our effort to restate a "realistic" approach to quantum mechanics, that would fully acknowledge that local realism is untenable, we add a few more questions and answers to the list presented in quant-ph/0203131. We also suggest to…

Quantum Physics · Physics 2016-09-08 Philippe Grangier

L. Vervoort [arxiv:1406.0901] claims to have found a model which "can violate the Bell inequality and reproduce the quantum statistics, even if it is based on local dynamics only". This claim is false. The proposed model contains global…

Quantum Physics · Physics 2017-01-27 I. Schmelzer

It was previously shown that models with deformations of special relativity that have an energy-dependent yet observer-independent speed of light suffer from nonlocal effects that are in conflict with observation to very high precision. In…

General Relativity and Quantum Cosmology · Physics 2010-05-05 Sabine Hossenfelder

Recently,the principle of nonviolation of information causality [Nature 461,1101 (2009)], has been proposed as one of the foundational properties of nature. We explore the Hardy's nonlocality theorem for two qubit systems, in the context of…

Quantum Physics · Physics 2013-01-17 Ali Ahanj , Samir Kunkri , Ashutosh Rai , Ramij Rahaman , Pramod S. Joag

Physical entities are ultimately (re)constructed from elementary yes/no events, in particular clicks in detectors or measurement devices recording quanta. Recently, the interpretation of certain such clicks has given rise to unfounded…

Quantum Physics · Physics 2012-03-02 Karl Svozil