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Related papers: Collective tests for quantum nonlocality

200 papers

We study the experimental signatures of several states of a Bose-Einstein condensate of spin-1 atoms by quantum trajectory simulations of Stern-Gerlach experiments. The measurement process itself creates an apparent random alignment for the…

Soft Condensed Matter · Physics 2009-10-31 Juha Javanainen

The Clauser-Horne-Shimony-Holt (CHSH) inequality is a constraint that local theories must obey. Quantum Mechanics predicts a violation of this inequality in certain experimental settings. Treatments of this subject frequently make…

Quantum Physics · Physics 2015-05-21 Peter Bierhorst

It is generally believed that dispersive polarimetric detection of collective angular momentum in large atomic spin systems gives rise to: squeezing in the measured observable, anti-squeezing in a conjugate observable, and collective spin…

Quantum Physics · Physics 2009-10-21 Ben Q. Baragiola , Bradley A. Chase , JM Geremia

Formulas for calculating the joint probability of outcomes of measurements performed on mutually non-interacting component systems of a combined system prepared in an entangled state are presented. The formulas are based on non-relativistic…

General Physics · Physics 2021-12-09 Zbigniew Zimpel

In previous articles we have developed a theory of down conversion in nonlinear crystals, based on the Wigner representation of the radiation field. Taking advantage of the fact that the Wigner function is always positive in parametric down…

Quantum Physics · Physics 2007-05-23 Alberto Casado , Trevor Marshall , Ramon Risco-Delgado , Emilio Santos

We show that correlations inconsistent with any locally causal description can be a generic feature of measurements on entangled quantum states. Specifically, spatially-separated parties who perform local measurements on a…

Quantum Physics · Physics 2016-09-08 Yeong-Cherng Liang , Nicholas Harrigan , Stephen D. Bartlett , Terry Rudolph

There have been studies on formation of quantum-nonlocal states in spatially separate two cavities. We suggest a nonlocal test for the field prepared in the two cavities. We couple classical driving fields with the cavities where a nonlocal…

Quantum Physics · Physics 2009-11-06 M. S. Kim , Jinhyoung Lee

In this paper, we study the bipartite entanglement of spin coherent states in the case of pure and mixed states. By a proper choice of the subsystem spins, the entanglement for large class of quantum systems is investigated. We generalize…

Quantum Physics · Physics 2015-06-12 K. Berrada , A. Mohammadzade , S. Abdel-Khalek , H. Eleuch , S. Salimi

We show that a pair of massive relativistic spin-1/2 particles prepared in a maximally entangled spin state in general is not capable of maximally violating the Clauser-Horne-Shimony-Holt (CHSH) version of Bell's inequalities without a…

Quantum Physics · Physics 2012-06-12 Pablo L. Saldanha , Vlatko Vedral

We investigate the violation of Bell-type inequalities for two-qubit Werner-like states parametrized by the positive parameter 0<p<1. We use an unbalanced homodyne detection scheme to obtain the quantum mechanical probabilities. A violation…

Quantum Physics · Physics 2009-11-13 Christoph F. Wildfeuer , Jonathan P. Dowling

We explore the possibility of achieving optimal joint measurements of noncommuting observables on a single quantum system by performing conventional measurements of commuting self adjoint operators on optimal clones of the original quantum…

Quantum Physics · Physics 2009-11-06 G. M. D'Ariano , C. Macchiavello , M. F. Sacchi

We show that for all $n\ge3$, an example of an $n$-partite quantum correlation that is not genuinely multipartite nonlocal but rather exhibiting anonymous nonlocality, that is, nonlocal but biseparable with respect to all bipartitions, can…

Quantum Physics · Physics 2014-09-26 Yeong-Cherng Liang , Florian John Curchod , Joseph Bowles , Nicolas Gisin

We study the power of local test for bipartite quantum states. Our central result is that, for properties of bipartite pure states, unitary invariance on one part implies an optimal (over all global testers) local tester acting only on the…

Quantum Physics · Physics 2025-06-02 Kean Chen , Qisheng Wang , Zhicheng Zhang

It is known that quantum correlations exhibited by a maximally entangled qubit pair can be simulated with the help of shared randomness, supplemented with additional resources, such as communication, post-selection or non-local boxes. For…

Quantum Physics · Physics 2009-11-11 Julien Degorre , Sophie Laplante , Jérémie Roland

A class of signed joint probability measures for n arbitrary quantum observables is derived and studied based on quasi-characteristic functions with symmetrized operator orderings of Margenau-Hill type. It is shown that the Wigner…

Quantum Physics · Physics 2024-10-01 Ralph Sabbagh , Olga Movilla Miangolarra , Hamid Hezari , Tryphon T. Georgiou

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 detection of nonlocal correlations in a Bell experiment implies almost by definition some intrinsic randomness in the measurement outcomes. For given correlations, or for a given Bell violation, the amount of randomness predicted by…

Quantum Physics · Physics 2018-08-20 Erik Woodhead , Boris Bourdoncle , Antonio Acín

A local hidden-variable model based on `isolato' hypothesis of the EPR--Bohm Gedanken experiment is presented. The `isolato' hypothesis states that one of a pair of spin-${1}/{2}$ particles can be in `isolato' mode in which the…

Quantum Physics · Physics 2015-06-26 Satoshi Uchiyama

Entanglement allows for the nonlocality of quantum theory, which is the resource behind device-independent quantum information protocols. However, not all entangled quantum states display nonlocality, and a central question is to determine…

Quantum Physics · Physics 2016-11-09 Daniel Cavalcanti , Leonardo Guerini , Rafael Rabelo , Paul Skrzypczyk

We investigate the trade-off between information gain and disturbance for a class of weak von Neumann measurements on spin-$\frac{1}{2}$ particles, and derive the unusual measurement pointer state that saturates this trade-off. We then…

Quantum Physics · Physics 2015-09-24 Ralph Silva , Nicolas Gisin , Yelena Guryanova , Sandu Popescu