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Related papers: Quantum correlations and causal structures

200 papers

Processes with indefinite causal order can arise when quantum theory is locally valid and they allow accomplishing new informational tasks. Despite recent progress, the correlations allowed in such processes have not been clearly…

Quantum Physics · Physics 2026-03-18 Zixuan Liu , Ognyan Oreshkov

Reconstructions of quantum theory usually implicitly assume that experimental events are ordered within a global causal structure. The process matrix framework accommodates quantum correlations that violate an inequality verified by all…

Quantum Physics · Physics 2015-11-24 Issam Ibnouhsein , Alexei Grinbaum

We study different notions of quantum correlations in multipartite systems of distinguishable and indistinguishable particles. Based on the definition of quantum coherence for a single particle, we consider two possible extensions of this…

Quantum Physics · Physics 2017-09-27 Jan Sperling , Armando Perez-Leija , Kurt Busch , Ian A. Walmsley

The characterization of quantum correlations is crucial to the development of new quantum technologies and to understand how dramatically quantum theory departs from classical physics. Here we systematically study single- and multiparticle…

Quantum Physics · Physics 2020-06-05 Rejane Alves de Brito , Bertúlio de Lima Bernardo

Epistemological consequences of quantum nonlocality (entanglement) are discussed under the assumption of a universally valid Schr\"odinger equation in the absence of hidden variables. This leads inevitably to a {\it many-minds…

Quantum Physics · Physics 2007-05-23 H. D. Zeh

Quantum coherence is an essential ingredient in quantum information processing and plays a central role in emergent fields such as nanoscale thermodynamics and quantum biology. However, our understanding and quantitative characterization of…

The study of quantum correlations within relativistic spacetimes, and the consequences of relativistic causality on information processing using such correlations, has gained much attention in recent years. In this paper, we establish a…

This work aims at exploring whether the nonlocal correlations due to quantum entanglement could exist without nonlocal causation. This is done with the aid of a toy model to investigate whether the ability of two quantum entangled particles…

General Physics · Physics 2025-03-25 Marco Pettini

The multipartite correlations derived from local measurements on some composite quantum systems are inconsistent with those reproduced classically. This inconsistency is known as quantum nonlocality and shows a milestone in the foundations…

Quantum Physics · Physics 2018-10-17 Ming-Xing Luo

A geometric interpretation for quantum correlations and entanglement according to a particular framework of emergent quantum mechanics is developed. The mechanism described is based on two ingredients: 1. At an hypothetical sub-quantum…

Quantum Physics · Physics 2020-07-20 Ricardo Gallego Torromé

We present a discussion on local quantum correlations and their relations with entanglement. We prove that vanishing coefficient of quantum correlations implies separability. The new results on locally decomposable maps which we obtain in…

Mathematical Physics · Physics 2009-11-10 W. A. Majewski

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

A century after the advent of Quantum Mechanics and General Relativity, both theories enjoy incredible empirical success, constituting the cornerstones of modern physics. Yet, paradoxically, they suffer from deep-rooted, so-far intractable,…

Quantum Physics · Physics 2017-03-20 Elizabeth S. Gould , Niayesh Afshordi

The idea that events obey a definite causal order is deeply rooted in our understanding of the world and at the basis of the very notion of time. But where does causal order come from, and is it a necessary property of nature? We address…

Quantum Physics · Physics 2013-02-15 Ognyan Oreshkov , Fabio Costa , Caslav Brukner

A continuous-variable Bell inequality, valid for an arbitrary number of observers measuring observables with an arbitrary number of outcomes, was recently introduced in [Cavalcanti \emph{et al.}, Phys. Rev. Lett. {\bf 99}, 210405 (2007)].…

Quantum Physics · Physics 2008-07-25 Alejo Salles , Daniel Cavalcanti , Antonio Acín

Long-range quantum correlations between particles are usually formulated by assuming the persistence of an entangled state after the particles have spearated. Here this approach is re-examined based upon studying the correlations present in…

Quantum Physics · Physics 2025-04-03 B. C. Sanctuary

The original purpose of measurements is to provide us with information about a previously unknown physical property of the system observed. In the Hilbert space formalism of quantum mechanics, this physical meaning of measurement…

Quantum Physics · Physics 2007-05-23 Holger F. Hofmann , Takayoshi Kobayashi , Akira Furusawa

Quantum correlations and other phenomena characteristic to a quantum world can be understood as simply consequences of a principle derived from the postulates of Quantum Mechanics. This explanatory principle states that these phenomena…

Quantum Physics · Physics 2014-07-01 Ovidiu-Cristinel Stoica

Quantum measurement is a physical process. What physical resources and constraints does quantum mechanics require for measurement to produce the classical world we observe? Treating measurement as a fully unitary quantum process, our goal…

Quantum Physics · Physics 2025-12-09 Vishal Johnson , Ashmeet Singh , Reimar Leike , Philipp Frank , Torsten Enßlin

Bell's theorem reveals a profound conflict between quantum mechanics and local realism, a conflict we reinterpret through the modern lens of causal inference. We propose and computationally validate a framework where quantum entanglement…

Quantum Physics · Physics 2025-08-28 Pilsung Kang