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Related papers: Locally inaccessible hidden quantum correlations

200 papers

Violation of Bell's inequality has been the mainspring for secure key generation in an entanglement assisted Quantum Key Distribution(QKD) protocol. Various contributions have relied on the violation of appropriate Bell inequalities to…

Quantum Physics · Physics 2023-04-19 Kaushiki Mukherjee , Tapaswini Patro , Nirman Ganguly

We show that a maximal violation of the Bell-CHSH inequality for two entangled qubits, i.e., Bell non-locality, is a direct consequence of a local bit erasure by means of a quasi-stochastic process, i.e., a stochastic process in which some…

Quantum Physics · Physics 2024-05-28 Kelvin Onggadinata , Pawel Kurzynski , Dagomir Kaszlikowski

We consider a general version of the phenomenon of more nonlocality with less entanglement, within the framework of the unambiguous (i.e., conclusive) quantum state discrimination problem under local quantum operations and classical…

Quantum Physics · Physics 2022-03-25 Saronath Halder , Ujjwal Sen

In this paper we consider the description by a general Bell-type non-local hidden variable theory (NLHVT) of bipartite quantum states with two observables per sub-system. We derive Bell inequalities of the…

Quantum Physics · Physics 2024-04-19 Bryan J Dalton

In a previous paper tests for entanglement for two mode systems involving identical massive bosons were obtained. In the present paper we consider sufficiency tests for EPR steering in such systems. We find that spin squeezing in any spin…

Quantum Physics · Physics 2020-01-22 Bryan J Dalton , Barry M Garraway , Margaret D Reid

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

Nonlocality and quantum entanglement constitute two special aspects of the quantum correlations existing in quantum systems, which are of paramount importance in quantum-information theory. Traditionally, they have been regarded as…

Quantum Physics · Physics 2015-05-27 J. Batle , M. Casas

The Bell inequality is thought to be a common constraint shared by all models of local hidden variables that aim to describe the entangled states of two qubits. Since the inequality is violated by the quantum mechanical description of these…

General Physics · Physics 2020-08-05 David H. Oaknin

We find two two-qubit states such that any number of copies of one state or the other cannot violate the CHSH Bell inequality. However, their tensor product can produce a CHSH violation of at least 2.023. We also identify a CHSH-local state…

Quantum Physics · Physics 2013-05-29 Miguel Navascues , Tamas Vertesi

Nonlocal quantum correlations among the quantum subsystems play essential roles in quantum science. The violation of the Svetlichny inequality provides sufficient conditions of genuine tripartite nonlocality. We provide tight upper bounds…

Quantum Physics · Physics 2021-01-26 Lingyun Sun , Li Xu , Jing Wang , Ming Li , Shuqian Shen , Lei Li , Shaoming Fei

We consider Bell tests in which the distant observers can perform local filtering before testing a Bell inequality. Notably, in this setup, certain entangled states admitting a local hidden variable model in the standard Bell scenario can…

Quantum Physics · Physics 2016-12-01 Flavien Hirsch , Marco Túlio Quintino , Joseph Bowles , Tamás Vértesi , Nicolas Brunner

We introduce a symmetric local hidden state $(slhs)$ model in a scenario, where two spacially separated parties receive quantum states from an unknown source. We derive an inequality based on the model. A completely new form of nonlocality…

Quantum Physics · Physics 2020-11-12 Debasis Mondal , Dagomir Kaszlikowski

The machinery of qubit-portraits of qudit states, recently presented, is consider here in more details in order to characterize the presence of quantum correlations in bipartite qudit states. In the tomographic representation of quantum…

Quantum Physics · Physics 2008-11-26 C. Lupo , V. I. Man'ko , G. Marmo

We derive a Bell-like inequality involving all correlations in local observables with uncertainty free states and show that the inequality is violated in quantum mechanics for EPR and GHZ states. If the uncertainties are allowed in local…

Quantum Physics · Physics 2007-05-23 Arun Kumar Pati

We present a novel inequality on the purity of a bipartite state depending solely on the difference of the local Bloch vector lengths. For two qubits this inequality is tight for all marginal states and so extends the previously known…

Quantum Physics · Physics 2024-01-23 Simon Morelli , Christopher Eltschka , Marcus Huber , Jens Siewert

We investigate the entanglement, CHSH nonlocality, fully entangled fraction and symmetric extendibility of two-qubit states that have a single maximally mixed marginal. Within this set of states, the steering ellipsoid formalism has…

Quantum Physics · Physics 2014-09-01 Antony Milne , David Jennings , Sania Jevtic , Terry Rudolph

While all bipartite pure entangled states violate some Bell inequality, the relationship between entanglement and non-locality for mixed quantum states is not well understood. We introduce a simple and efficient algorithmic approach for the…

Quantum Physics · Physics 2009-11-07 Barbara M. Terhal , Andrew C. Doherty , David Schwab

The aim of this thesis is to investigate quantum entanglement and quantum nonlocality of bipartite finite-dimensional systems (bipartite qudits). Entanglement is one of the most fascinating non-classical features of quantum theory, and…

Quantum Physics · Physics 2009-07-09 Christoph Spengler

Quantum violation of Bell inequalities is now used in many quantum information applications and it is important to analyze it both quantitatively and conceptually. In the present paper, we analyze violation of multipartite Bell inequalities…

Quantum Physics · Physics 2018-03-28 Elena R. Loubenets

We discuss the relations between the violation of the CHSH Bell inequality for systems of two qubits on the one side and entanglement of formation, local filtering operations, and the entropy and purity on the other. We calculate the…

Quantum Physics · Physics 2009-11-07 Frank Verstraete , Michael M. Wolf