English
Related papers

Related papers: Characterizing high-dimensional quantum contextual…

200 papers

We discuss three measures of the degree of contextuality in contextual systems of dichotomous random variables. These measures are developed within the framework of the Contextuality-by-Default (CbD) theory, and apply to inconsistently…

Quantum Physics · Physics 2020-10-20 Janne V. Kujala , Ehtibar N. Dzhafarov

Beginning with the Bell theorem, cyclic systems of dichotomous random variables have been the object of many foundational findings in quantum mechanics. Here, we ask the question: if one chooses a cyclic system "at random" (uniformly within…

Quantum Physics · Physics 2021-04-14 Ehtibar N. Dzhafarov , Janne V. Kujala , Víctor H. Cervantes

The existence of observables that are incompatible or not jointly measurable is a characteristic feature of quantum mechanics, which lies at the root of a number of nonclassical phenomena, such as uncertainty relations, wave--particle dual…

Quantum Physics · Physics 2015-11-17 Huangjun Zhu

Quantum resources can improve communication complexity problems (CCPs) beyond their classical constraints. One quantum approach is to share entanglement and create correlations violating a Bell inequality, which can then assist classical…

It is well known that correlations predicted by quantum mechanics cannot be explained by any classical (local-realistic) theory. The relative strength of quantum and classical correlations is usually studied in the context of Bell…

Combining recent advances in superconducting quantum hardware, we explore quantum correlations in a previously inaccessible regime by observing \emph{simultaneously} high-dimensional and many-body Bell non-locality. We report a…

Quantum Physics · Physics 2026-04-28 Yousef Mafi , Ali G. Moghaddam , Teemu Ojanen

We study the role of context, complex of physical conditions, in quantum as well as classical experiments. It is shown that by taking into account contextual dependence of experimental probabilities we can derive the quantum rule for the…

High Energy Physics - Theory · Physics 2009-11-07 Andrei Khrennikov

Contextuality is a fundamental feature of quantum theory and is necessary for quantum computation and communication. Serious steps have therefore been taken towards a formal framework for contextuality as an operational resource. However,…

Quantum Physics · Physics 2018-04-26 Barbara Amaral , Adán Cabello , Marcelo Terra Cunha , Leandro Aolita

We present and experimentally demonstrate a novel non-classical phenomenon, bi-contextuality, observed in quantum systems prepared by two independent sources. This discovery plays a key role in the developing framework of network…

We show that there are Bell-type inequalities for noncontextual theories that are violated by any quantum state. One of these inequalities between the correlations of compatible measurements is particularly suitable for testing this…

Quantum Physics · Physics 2009-07-28 Adan Cabello

Quantum contextuality provides a fundamental signature of nonclassical behavior that cannot be explained by noncontextual hidden-variable models. We propose and experimentally implement a linear-optical setup for demonstrating…

Quantum Physics · Physics 2026-05-19 Jiaqi Liu , Bita Olamaei , Lijian Zhang , Ali Asadian , Saleh Rahimi-Keshari

Quantum correlations in Bell and prepare-and-measure experiments are central resources for probing nonclassicality and enabling device-based quantum information protocols. In the absence of shared public randomness (i.e., without run-to-run…

Quantum Physics · Physics 2026-04-21 Liang-Liang Sun , Xiang Zhou , Chengjie Zhang , Zizhu Wang , Yong-Shun Song , Sixia Yu

It is well known that the effect of quantum nonlocality, as witnessed by violation of a Bell inequality, can be observed even when relaxing the assumption of measurement independence, i.e. allowing for the source to be partially correlated…

Quantum Physics · Physics 2023-11-17 Ivan Šupić , Jean-Daniel Bancal , Nicolas Brunner

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

The predictions of quantum theory resist generalised noncontextual explanations. In addition to the foundational relevance of this fact, the particular extent to which quantum theory violates noncontextuality limits available quantum…

Quantum Physics · Physics 2021-06-30 Anubhav Chaturvedi , Máté Farkas , Victoria J Wright

We describe a cohomological framework for measurement based quantum computation, in which symmetry plays a central role. Therein, the essential information about the computational output is contained in topological invariants, namely…

Quantum Physics · Physics 2019-12-23 Robert Raussendorf

Contextuality is a phenomenon at the heart of the quantum mechanical departure from classical behaviour, and has been recently identified as a resource in quantum computation. Experimental demonstration of contextuality is thus an important…

Quantum Physics · Physics 2019-03-26 Xiang Zhan , Eric G. Cavalcanti , Jian Li , Zhihao Bian , Yongsheng Zhang , Howard M. Wiseman , Peng Xue

We employ the resource theory of generalized contextuality as a tool for analyzing the structure of prepare-and-measure scenarios. We argue that this framework simplifies proofs of quantum contextuality in complex scenarios and strengthens…

Quantum Physics · Physics 2023-11-29 Rafael Wagner , Roberto D. Baldijão , Alisson Tezzin , Bárbara Amaral

In this work, we elaborate on a measure-theoretic approach to negative probabilities. We study a natural notion of contextuality measure and characterize its main properties. Then, we apply this measure to relevant examples of quantum…

Quantum Physics · Physics 2023-02-02 Elisa Monchietti , César Massri , J. Acacio de Barros , Federico Holik

We introduce a notion of contextuality for transformations in sequential contexts, distinct from the Bell-Kochen-Specker and Spekkens notions of contextuality. Within a transformation-based model for quantum computation we show that strong…

Quantum Physics · Physics 2018-12-12 Shane Mansfield , Elham Kashefi