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Related papers: Bell non-locality and Kochen-Specker contextuality…

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Contextuality and measurement incompatibility are two fundamental aspects of nonclassicality, and their manifestations in observed quantum correlations are often deeply interconnected. Recently, measurement incompatibility has been studied…

Quantum Physics · Physics 2026-04-07 Swati Kumari , Sumit Mukherjee , R. Prabhu

The characterization of quantum correlations, being stronger than classical, yet weaker than those appearing in non-signaling models, still poses many riddles. In this work we show that the extent of binary correlations in a general class…

Quantum Physics · Physics 2018-07-17 Avishy Carmi , Eliahu Cohen

We propose a method to generate analytical quantum Bell inequalities based on the principle of Macroscopic Locality. By imposing locality over binary processings of virtual macroscopic intensities, we establish a correspondence between Bell…

Quantum Physics · Physics 2011-02-17 Tzyh Haur Yang , Miguel Navascués , Lana Sheridan , Valerio Scarani

The Kochen-Specker theorem, Bell inequalities, and several other tests that were designed to rule out hidden-variable theories, assume the existence of observables having infinitely sharp eigenvalues. A paradigmatic example is spin-1/2. It…

Quantum Physics · Physics 2014-10-03 F. De Zela

We explore non-classical correlations in n-cycle setting. In particular, we focus on correlations manifested by Kochen-Specker-Klyachko box (KS box), scenarios involving n-cycle non-contextuality inequalities and Popescu-Rohlrich boxes (PR…

Quantum Physics · Physics 2019-02-19 Kishor Bharti , Maharshi Ray , Leong Chuan Kwek

Contextuality is central to both the foundations of quantum theory and to the novel information processing tasks. Although it was recognized before Bell's nonlocality, despite some recent proposals, it still faces a fundamental problem: how…

Quantum Physics · Physics 2014-04-02 A. Grudka , K. Horodecki , M. Horodecki , P. Horodecki , R. Horodecki , P. Joshi , W. Kłobus , A. Wójcik

Quantum systems show contextuality. More precisely, it is impossible to reproduce the quantum-mechanical predictions using a non-contextual realist model, i.e., a model where the outcome of one measurement is independent of the choice of…

Quantum Physics · Physics 2014-09-25 Jan-Åke Larsson

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

A standard approach in the foundations of quantum mechanics studies local realism and hidden variables models exclusively in terms of violations of Bell-like inequalities. Thus quantum nonlocality is tied to the celebrated no-go theorems,…

Quantum Physics · Physics 2007-05-23 James D. Malley , Arthur Fine

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 consider an ontology, in which contextual nonlocal hidden variables are stored as pre-existing possibilities in a repository outside space-time; and in which the context can be chosen ``freely'' (measurement independence) by each agent,…

Quantum Physics · Physics 2026-05-11 Valerio Scarani , Antoine Suarez

Bell's theorem shows that local measurements on entangled states give rise to correlations incompatible with local hidden variable models. The degree of quantum nonlocality is not maximal though, as there are even more nonlocal theories…

Quantum Physics · Physics 2018-12-26 Cristhiano Duarte , Samuraí Brito , Barbara Amaral , Rafael Chaves

The causal structure of any experiment implies restrictions on the observable correlations between measurement outcomes, which are different for experiments exploiting classical, quantum, or post-quantum resources. In the study of Bell…

As is well known, quantum mechanical behavior cannot, in general, be simulated by a local hidden variables model. Most -if not all- the proofs of this incompatibility refer to the correlations which arise when each of two (or more) systems…

Quantum Physics · Physics 2016-09-08 Sandu Popescu

Here it is shown that the simplest description of Bell's experiment according to the canon of von Neumann's theory of measurement explicitly assumes the (Quantum Mechanics-language equivalent of the classical) condition of Locality. This…

Quantum Physics · Physics 2020-02-28 Alejandro Hnilo

The boundary between classical and quantum correlations is well characterised by linear constraints called Bell inequalities. It is much harder to characterise the boundary of the quantum set itself in the space of no-signaling…

Quantum Physics · Physics 2016-08-25 Yi-Zheng Zhen , Koon Tong Goh , Yu-Lin Zheng , Wen-Fei Cao , Xingyao Wu , Kai Chen , Valerio Scarani

In contrast to conventional, dynamical entanglement, in which particles with definite identity have uncertain properties, in so-called statistical entanglement, which arises between indistinguishable particles because of quantum symmetry…

Quantum Physics · Physics 2012-01-25 R. Srikanth , Debajyoti Gangopadhyay

Contextuality is a defining feature that separates the quantum from the classical descriptions of physical systems. Within the marginal-scenario framework, noncontextual models are characterized by the existence of a single joint…

Quantum Physics · Physics 2026-04-08 Andrea Navoni , Marco G. Genoni , Andrea Smirne

Recent experiments have demonstrated ququart state-independent quantum contextuality and qutrit state-dependent quantum contextuality. So far, the most basic form of quantum contextuality pointed out by Kochen and Specker, and Bell, has…

Quantum Physics · Physics 2012-03-06 Adan Cabello , Elias Amselem , Kate Blanchfield , Mohamed Bourennane , Ingemar Bengtsson

As a phenomenon encompassing measurement incompatibility and Bell nonlocality, quantum contextuality is not only central to our understanding of quantum mechanics, but also an essential resource in many quantum information processing tasks.…

Quantum Physics · Physics 2024-03-19 Xiao-Dong Yu , Isadora Veeren , Otfried Gühne