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Related papers: Bell's inequality without alternative settings

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We present a universal algorithm for the optimal quantum state estimation of an arbitrary finite dimensional system. The algorithm specifies a physically realizable positive operator valued measurement (POVM) on a finite number of…

Quantum Physics · Physics 2009-10-30 Radoslav Derka , Vladimir Buzek , Artur Ekert

We remind the viewpoint that violation of Bell's inequality might be interpreted not only as an evidence of the alternative -- either nonlocality or ``death of reality'' (under the assumption the quantum mechanics is incomplete). Violation…

Quantum Physics · Physics 2010-08-03 Andrei Khrennikov

I give a first characterization of the class of generalized measurements that can be exactly realized on a pair of qudits encoded in indistinguishable particles, by using only linear elements and particle detectors. Two immediate results…

Quantum Physics · Physics 2009-11-07 John Calsamiglia

Device-independent (DI) quantum protocols exploit Bell inequality violations to ensure security or certify quantum properties without making assumptions about the internal workings of the devices. In this work, we study the role of rank-one…

We show that a one-dimensional discrete time quantum walk can be used to implement a generalized measurement in terms of positive operator value measure (POVM) on a single qubit. More precisely, we show that for a single qubit any set of…

Quantum Physics · Physics 2013-05-22 Pawel Kurzynski , Antoni Wojcik

We propose an EPR inequality based on an entropic uncertainty relation for complementary continuous variable observables. This inequality is more sensitive than the previously established EPR inequality based on inferred variances, and…

Quantum Physics · Physics 2009-07-27 S. P. Walborn , A. Salles , R. M. Gomes , F. Toscano , P. H. Souto Ribeiro

Unarticulated, implicit hypotheses in Bell's analysis of Einstein, Podolsky and Rosen (EPR) correlations are identified and examined. These relate to the mathematical-analytical properties of random variables, the character of the relevant…

Quantum Physics · Physics 2007-05-23 A. F. Kracklauer , N. A. Kracklauer

The most general type of measurement in quantum physics is modeled by a positive operator-valued measure (POVM). Mathematically, a POVM is a generalization of a measure, whose values are not real numbers, but positive operators on a Hilbert…

Logic in Computer Science · Computer Science 2014-12-31 Frank Roumen

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

Bell's theorem reveals contradictions between the predictions of quantum mechanics and the EPR postulates for a pair of particles only in situations involving imperfect statistical correlations. However, with three or more particles,…

Optics · Physics 2009-11-11 P. Hariharan , J. Samuel , Supurna Sinha

In this work, we examine the paradox proposed by Einstein, Podolsky, and Rosen (EPR). They argued that since one may know the exact momentum of a particle without measurement and subsequently measure its position, a contradiction with the…

Quantum Physics · Physics 2026-04-07 Henryk Gzyl

Most physicists agree that the Einstein-Podolsky-Rosen-Bell paradox exemplifies much of the strange behavior of quantum mechanics, but argument persists about what assumptions underlie the paradox. To clarify what the debate is about, we…

Quantum Physics · Physics 2015-05-13 Guy Blaylock

We established a physically utilizable Bell inequality based on the Peres-Horodecki criterion. The new quadratic probabilistic Bell inequality naturally provides us a necessary and sufficient way to test all entangled two-qubit or…

Quantum Physics · Physics 2007-06-22 Jing-Ling Chen , Ming-Guang Hu

A solution to the second measurement problem, determining what prior microscopic properties can be inferred from measurement outcomes ("pointer positions"), is worked out for projective and generalized (POVM) measurements, using consistent…

Quantum Physics · Physics 2017-09-20 Robert B. Griffiths

We use entropic uncertainty relations to formulate inequalities that witness Einstein-Podolsky-Rosen (EPR) steering correlations in diverse quantum systems. We then use these inequalities to formulate symmetric EPR-steering inequalities…

We introduce a concept of a minimal sufficient positive-operator valued measure (POVM), which is the least redundant POVM among the POVMs that have the equivalent information about the measured quantum system. Assuming the system Hilbert…

Quantum Physics · Physics 2015-10-26 Yui Kuramochi

Bell tests---the experimental demonstration of a Bell inequality violation---are central to understanding the foundations of quantum mechanics, underpin quantum technologies, and are a powerful diagnostic tool for technological developments…

The no-signalling principle is a fundamental assumption in Bell-inequality and quantum-steering experiments. Nonetheless, experimental imperfections can lead to apparent violations beyond those expected from finite-sample statistics. Here,…

We introduce several notions of random positive operator valued measures (POVMs), and we prove that some of them are equivalent. We then study statistical properties of the effect operators for the canonical examples, obtaining limiting…

Quantum Physics · Physics 2020-04-27 Teiko Heinosaari , Maria Anastasia Jivulescu , Ion Nechita

It is commonly believed that the most general type of a quantum-mechanical measurement is one described by a positive-operator valued measure (POVM). In the present paper, this statement is proven for any measurements on quantum systems…

Quantum Physics · Physics 2014-02-13 A. V. Nenashev