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Related papers: Witnessing non-classicality beyond quantum theory

200 papers

We analyze interrelation of quantum and classical entanglement. The latter notion is widely used in classical optic simulation of some quantum-like features of light. We criticize the common interpretation that "quantum nonlocality" is the…

Quantum Physics · Physics 2021-03-26 Andrei Khrennikov

We devise a protocol in which general non-classical multipartite correlations produce a physically relevant effect, leading to the creation of bipartite entanglement. In particular, we show that the relative entropy of quantumness, which…

Two of us recently proposed an entanglement-based witness of non-classicality, which can be applied to testing quantum effects in gravity in what is known as the Bose-Marletto-Vedral (BMV) effect. The witness is based on this idea: if a…

Quantum Physics · Physics 2024-11-05 Giuseppe Di Pietra , Vlatko Vedral , Chiara Marletto

Quantum theory demands that, in contrast to classical physics, not all properties can be simultaneously well defined. The Heisenberg Uncertainty Principle is a manifestation of this fact. Another important corollary arises that there can be…

We generalize the classical probability frame by adopting a wider family of random variables that includes nondeterministic ones. The frame that emerges is known to host a ''classical'' extension of quantum mechanics. We discuss the notion…

Quantum Physics · Physics 2007-05-23 E. G. Beltrametti , S. Bugajski

Characterizing genuine quantum resources and determining operational rules for their manipulation are crucial steps to appraise possibilities and limitations of quantum technologies. Two such key resources are nonclassicality, manifested as…

Experiments have recently been proposed testing whether quantum gravitational interactions generate entanglement between adjacent masses in position superposition states. We propose potentially less challenging experiments that test quantum…

General Relativity and Quantum Cosmology · Physics 2021-05-03 Adrian Kent

In [M. Piani et al., arXiv:1103.4032 (2011)] an activation protocol was introduced which maps the general non-classical (multipartite) correlations between given systems into bipartite entanglement between the systems and local ancillae by…

Quantum Physics · Physics 2013-04-19 Sevag Gharibian , Marco Piani , Gerardo Adesso , John Calsamiglia , Pawel Horodecki

Nature allows one to explore a manifold of remarkable quantum effects. Most prominently, quantum entanglement can be observed in many-particle systems, between multiple quantized fields, and in hybrid combinations thereof. This diversity,…

Quantum Physics · Physics 2023-05-04 Jan Sperling , Elizabeth Agudelo

Quantum mechanics exhibits a wide range of nonclassical features, of which entanglement in multipartite systems takes a central place. In several specific settings, it is well known that nonclassicality (e.g., squeezing, spin squeezing,…

Quantum Physics · Physics 2016-02-25 Nathan Killoran , Frank E. S. Steinhoff , Martin B. Plenio

Recent proposals in quantum gravity have suggested that unknown systems can mediate entanglement between two known quantum systems, if and only if the mediator itself is non-classical. This approach may be applicable to the brain, where…

General Physics · Physics 2022-10-05 Christian Kerskens , David Lopez Perez

We address the following criterion for quantifying the quantum information resources: classically simulable {\it vs.} classically non-simulable information processing. This approach gives rise to existence of a deeper level of quantum…

Quantum Physics · Physics 2007-05-23 M. Dugic

We develop a new formalism for constructing probabilities associated to the causal ordering of events in quantum theory, where by an event we mean the emergence of a measurement record on a detector. We start with constructing probabilities…

Quantum Physics · Physics 2024-01-17 Charis Anastopoulos , Maria_Electra Plakitsi

A recent paper published on Nature [Nature,646,813(2025)] by Aziz and Howl, claims that quantum particles become entangled when they interact gravitationally, even if the gravitational potential is treated classically. We show that the…

Quantum Physics · Physics 2026-04-22 Anirudh Gundhi , Giorgia Infantino , Angelo Bassi

We present a notion of generalized entanglement which goes beyond the conventional definition based on quantum subsystems. This is accomplished by directly defining entanglement as a property of quantum states relative to a distinguished…

Quantum Physics · Physics 2007-05-23 Lorenza Viola , Howard Barnum , Emanuel Knill , Gerardo Ortiz , Rolando Somma

The expected indefinite causal structure in quantum gravity poses a challenge to the notion of entanglement: If two parties are in an indefinite causal relation of being spacelike and timelike, can they still be entangled? If so, how does…

Quantum Physics · Physics 2018-02-27 Ding Jia

One interpretation of how the classical world emerges from an underlying quantum reality involves the build-up of certain robust entanglements between particles due to scattering events [Science Vol.301 p.1081]. This is an appealing view…

Quantum Physics · Physics 2013-04-26 P. A. Knott , J. Sindt , J. A. Dunningham

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

The aim of this article is to provide an introduction to the use of quantum information methods for investigating the interface between quantum theory and gravity. To this end, we discuss the basic principles of two current research streams…

Quantum Physics · Physics 2025-12-24 Bruna Sahdo , Natália Salomé Móller

Quantum correlations can be stronger than anything achieved by classical systems, yet they are not reaching the limit imposed by relativity. The principle of information causality offers a possible explanation for why the world is quantum…

Quantum Physics · Physics 2014-11-12 Martin Ringbauer , Alessandro Fedrizzi , Dominic W. Berry , Andrew G. White