English
Related papers

Related papers: Quantum Counterfactuals and Locality

200 papers

Quantum mechanics allows systems to be entangled with each other, which results in stronger than classical correlations. Many methods of identifying entanglement have been proposed over years, most of which are based on violating some…

Quantum Physics · Physics 2014-12-31 Ramij Rahaman , Marcin Wieśniak , Marek Żukowski

In this paper, we study the Hardy nonlocal argument (HNA) and the Cabello nonlocal argument (CNA) under the Information Causality, Macroscopic Locality and Local Orthogonality principles in the context of Local Randomness. We see that, in…

Quantum Physics · Physics 2017-09-05 Ali Ahanj

Since the pillars of quantum theory were established, it was already noted that quantum physics may allow certain correlations defying any local realistic picture of nature, as first recognized by Einstein, Podolsky and Rosen. These quantum…

Here we deal with a nonlocality argument proposed by Cabello which is more general than Hardy's nonlocality argument but still maximally entangled states do not respond. However, for most of the other entangled states maximum probability of…

Quantum Physics · Physics 2009-11-11 Samir Kunkri , Sujit K. Choudhary , Ali Ahanj , Promod Joag

I purport to show why old and new claims on the role of counterfactual reasoning for the EPR argument and the Bell theorem are unjustified: once the logical relation between locality and counterfactual reasoning is clarified, the use of the…

Quantum Physics · Physics 2017-05-24 Federico Laudisa

We show that local realism applied to states characterized by a single quanta equally and coherently shared between a number of qubits (so-called W states) produces predictions incompatible with quantum theory. The origin of this…

Quantum Physics · Physics 2011-03-29 G. S. Paraoanu

Study of nonlocal correlations in term of Hardy's argument has been quite popular in quantum mechanics. Recently Hardy's argument of non-locality has been studied in the context of generalized non-signaling theory as well as theory…

Quantum Physics · Physics 2013-01-17 MD. Rajjak Gazi , Ashutosh Rai , Samir Kunkri , Ramij Rahaman

Contextuality and nonlocality are two fundamental properties of nature. Hardy's proof is considered the simplest proof of nonlocality and can also be seen as a particular violation of the simplest Bell inequality. A fundamental question is:…

Quantum Physics · Physics 2013-11-01 Adan Cabello , Piotr Badziag , Marcelo Terra Cunha , Mohamed Bourennane

Quantum mechanics is nonlocal. Classical mechanics is local. Consequently classical mechanics can not explain all quantum phenomena. Conversely, it is cumbersome to use quantum mechanics to describe classical phenomena. Not only are the…

Quantum Physics · Physics 2007-05-23 Nicolas Gisin , Todd A. Brun , Marco Rigo

A qualification is suggested for the counterfactual reasoning involved in some aspects of time-symmetric quantum theory (which involves ensembles selected by both the initial and final states). The qualification is that the counterfactual…

Quantum Physics · Physics 2007-05-23 D. J. Miller

Quantum theory departs from classical physics in its treatment of correlations, most prominently through the phenomena of contextuality and nonlocality. Once regarded primarily as foundational curiosities, these effects are now understood…

Quantum Physics · Physics 2026-02-27 Jianqi Sheng , Dongkai Zhang , Lixiang Chen

I have been arguing that quantum nonlocality, deeply entrenched in the present formalism of quantum mechanics and widely believed as a reality by physicists, is in fact absent. Spooky nonlocal state reduction is the most, and perhaps the…

Quantum Physics · Physics 2007-05-23 C . S. Unnikrishnan

If Nature allowed nonlocal correlations other than those predicted by quantum mechanics, would that contradict some physical principle? Various approaches have been put forward in the past two decades in an attempt to single out quantum…

Quantum Physics · Physics 2019-04-19 Avishy Carmi , Eliahu Cohen

Departing from the usual paradigm of local operations and classical communication adopted in entanglement theory, here we study the interconversion of quantum states by means of local operations and shared randomness. A set of necessary and…

Quantum Physics · Physics 2012-05-18 Francesco Buscemi

Quantum entanglement and nonlocality are inequivalent notions: There exist entangled states that nevertheless admit local-realistic interpretations. This paper studies a special class of local-hidden-variable theories, in which the linear…

Quantum Physics · Physics 2017-11-17 Bin Yan

In this study, we study weak values from a quantum-logical viewpoint. In addition, we examine the validity of the counterfactual statements of Hardy's paradox, which are based on weak values, and we show that these statements have not been…

Quantum Physics · Physics 2013-07-23 Riuji Mochizuki

H. P. Stapp has proposed a number of demonstrations of a Bell-type theorem which dispensed with an assumption of hidden variables, but relied only upon locality together with an assumption that experimenters can choose freely which of…

Quantum Physics · Physics 2007-05-23 Abner Shimony

A discussion of the quantum mechanical use of superposition or entangled states shows that descriptions containing only statements about state vectors and experiments outputs are the most suitable for Quantum Mechanics. In particular, it is…

Quantum Physics · Physics 2008-05-25 Giuseppe Giuliani

Depending on the way one measures, quantum nonlocality might manifest more visibly. Using basis transformations and interactions on a particle pair, Hardy logically argued that any local hidden variable theory leads to a paradox. Extended…

Quantum Physics · Physics 2023-04-18 Duc Minh Tran , Van-Duy Nguyen , Le Bin Ho , Hung Q. Nguyen

Can quantum theory be applied on all scales? While there are many arguments for the universality of quantum theory, this question remains a subject of debate. It is unknown how far the existence of macroscopic irreversibility can be derived…

Quantum Physics · Physics 2025-05-30 Maria Violaris