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Related papers: State-independent quantum contextuality and maximu…

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Contextuality is one way of capturing the non-classicality of quantum theory. The contextual nature of a theory is often witnessed via the violation of non-contextuality inequalities---certain linear inequalities involving probabilities of…

Quantum Physics · Physics 2020-07-08 Kishor Bharti , Atul Singh Arora , Leong Chuan Kwek , Jérémie Roland

Fully revealing the mathmatical structure of quantum contextuality is a significant task, while some known contextuality theories are only applicable for rank-1 projectors. That is because they adopt the observable-based definitions. This…

Quantum Physics · Physics 2025-01-17 Songyi Liu , Yongjun Wang , Baoshan Wang , Yunyi Jia

We show that three unsharp binary qubit measurements are enough to violate a generalized noncontextuality inequality, the LSW inequality, in a state-dependent manner. For the case of trine spin axes we calculate the optimal quantum…

Quantum Physics · Physics 2014-05-15 Ravi Kunjwal , Sibasish Ghosh

From the consideration of measuring bipartite mixed states by separable pure states, we introduce algebraic sets in complex projective spaces for bipartite mixed states as the degenerating locus of the measurement. These algebraic sets are…

Quantum Physics · Physics 2007-05-23 Hao Chen

So far, most of the literature on (quantum) contextuality and the Kochen-Specker theorem seems either to concern particular examples of contextuality, or be considered as quantum logic. Here, we develop a general formalism for contextuality…

Quantum Physics · Physics 2015-02-10 Antonio Acín , Tobias Fritz , Anthony Leverrier , Ana Belén Sainz

We show that there is a stronger form of bipartite quantum nonlocality in which systems that never interacted are as nonlocal as allowed by no-signaling. For this purpose, we first show that nonlocal boxes, theoretical objects that violate…

Quantum Physics · Physics 2012-11-26 Adan Cabello

In this paper, we find the necessary and sufficient condition for the maximal entanglement of the state, $ |\psi>=\mu|\alpha>|\beta>+\lambda|\alpha>|\delta>+ \rho|\gamma>|\beta>+\nu|\gamma>|\delta>,$ constructed by linearly independent…

Quantum Physics · Physics 2011-04-28 G. Najarbashi , Y. Maleki

The non-classicality of single quantum systems can be formalised using the notion of contextuality. But can contextuality be convincingly demonstrated in an experiment, without reference to the quantum formalism? The operational approach to…

Quantum Physics · Physics 2019-04-19 Matthew F. Pusey , Lídia del Rio , Bettina Meyer

Contextuality - the obstruction to describing quantum mechanics in a classical statistical way - has been proposed as a resource that powers quantum computing. The measurement-based model provides a concrete manifestation of contextuality…

Quantum Physics · Physics 2018-10-12 Markus Frembs , Sam Roberts , Stephen D. Bartlett

Two fundamental quantum resources, nonlocality and contextuality, can be connected through Bell inequalities that are violated by state-independent contextuality (SI-C) sets. These Bell inequalities allow for applications that require…

Quantum Physics · Physics 2023-03-24 Junior R. Gonzales-Ureta , Ana Predojević , Adán Cabello

The problem of detecting non-classical correlations of states of many qudits is incomparably more involved than in a case of qubits. The reason is that for qubits we have a convenient description of the system by the means of the…

Quantum Physics · Physics 2016-10-27 Krzysztof Rosołek , Marcin Wieśniak , Lukas Knips

We explore the relationship between Kochen-Specker quantum contextuality and Bell-nonclassicality for ensembles of two-qubit pure states. We present a comparative analysis showing that the violation of a noncontextuality inequality on a…

Quantum Physics · Physics 2024-02-26 Giovanni Scala , Antonio Mandarino

Quantum mechanics provides a statistical description about nature, and thus would be incomplete if its statistical predictions could not be accounted for by some realistic models with hidden variables. There are, however, two powerful…

Quantum Physics · Physics 2012-10-04 Xi Kong , Mingjun Shi , Fazhan Shi , Pengfei Wang , Pu Huang , Qi Zhang , Chenyong Ju , Changkui Duan , Sixia Yu , Jiangfeng Du

We derive a general framework to identify genuinely multipartite entangled mixed quantum states in arbitrary-dimensional systems and show in exemplary cases that the constructed criteria are stronger than those previously known. Our…

Quantum Physics · Physics 2013-05-29 Marcus Huber , Florian Mintert , Andreas Gabriel , Beatrix C. Hiesmayr

Quantum correlation provides a promising measure beyond entanglement. Here, we propose a necessary and sufficient condition for nonzero quantum correlation in continuous variable systems, which is simple and easy to perform in terms of a…

Quantum Physics · Physics 2015-11-12 Chengjie Zhang , Sixia Yu , Qing Chen , Haidong Yuan , C. H. Lai , C. H. Oh

We present a general method to characterize the quantum correlations obtained after local measurements on multipartite systems. Sufficient conditions for a quantum system to be fully-nonlocal according to a given partition, as well as being…

Quantum Physics · Physics 2015-05-14 Mafalda L. Almeida , Daniel Cavalcanti , Valerio Scarani , Antonio Acin

Based on the generalized Bloch representation, we study the separability and entanglement of arbitrary dimensional multipartite quantum states. Some sufficient and some necessary criteria are presented. For certain states, these criteria…

Quantum Physics · Physics 2025-09-09 Zhi-Bo Chen , Shao-Ming Fei

Random numbers represent an indispensable resource for many applications. A recent remarkable result is the realization that non-locality in quantum mechanics can be used to certify genuine randomness through Bell's theorem, producing…

Quantum Physics · Physics 2013-01-28 D. -L. Deng , C. Zu , X. -Y. Chang , P. -Y. Hou , H. -X. Yang , Y. -X. Wang , L. -M. Duan

Quantum contextual sets have been recognized as resources for universal quantum computation, quantum steering and quantum communication. Therefore, we focus on engineering the sets that support those resources and on determining their…

Quantum Physics · Physics 2023-03-20 Mladen Pavicic

In this work we analyze a non-commutativity measure of quantum correlations recently proposed by Y. Guo [Sci. Rep. 6, 25241 (2016)]. By recourse to a systematic survey of a two-qubit system, we detected an undesirable behavior of such a…

Quantum Physics · Physics 2017-08-25 A. P. Majtey , D. Bussandri , T. M. Osán , P. W. Lamberti , A. Valdés-Hernández