Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

On instantaneous Bell measurements

Karl Svozil

Published Jun 12, 2002• 0 citations
OpenAlex

Abstract

All experimental tests of Bell-type inequalities and Greenberger-Horne-Zeilinger setups rely on the separate and successive measurement of the terms involved. We discuss possibilities of experimental setups to measure all relevant terms simultaneously in a single experiment and find this to be impossible. One reason is the lack of multi-partite states which are unique in the sense that a measurement of some observable on one particle fixes the value of the corresponding observables of the other particles as well.

Related papers

Are simultaneous Bell measurements possible?

Karl Svozil

All experimental tests of Bell-type inequalities and Greenberger–Horne–Zeilinger setups rely on the separate and successive measurement of the terms involved. We discuss possibilities of experimental setups to measure all relevant terms simultaneously in a single experiment and find this to be impossible. One reason is the lack of multi-partite states which are unique in the sense that a measurement of some observable on one particle fixes the value of the corresponding observables of the other particles as well.

arXiv:quant-ph/0206076•New Journal of Physics•Mar 10, 2006•19 citations

Optimal tests of quantum nonlocality

Itamar Pitowsky, Karl Svozil

We present a general method for obtaining all Bell inequalities for a given experimental setup. Although the algorithm runs slowly, we apply it to two cases. First, the Greenberger-Horne-Zeilinger setup with three observers each performing one of two possible measurements. Second, the case of two observers each performing one of three possible experiments. In both cases we obtain hundreds of inequalities. Since this is the set of all inequalities, the one that is maximally violated in a given quantum state must be among them. We demonstrate this fact with a few examples. We also note the deep connection between the inequalities and classical logic, and their violation with quantum logic.

arXiv:quant-ph/0011060•Physical Review A•Jun 7, 2001•160 citations

Bell theorem involving all possible local measurements

Dagomir Kaszlikowski, Marek Żukowski

The Bell theorem for a pair of two-state systems in a singlet state is formulated for the entire range of measurement settings.

arXiv:quant-ph/9908009•Physical Review A•Jan 14, 2000•15 citations

Experimentally Testable State-Independent Violation of Bell-Type Inequalities for Quantum Contextuality

Adán Cabello

There are experimentally testable correlation Bell inequalities which are satisfied by any noncontextual theory but are violated by any quantum state. We discuss how to test one of them.

International Conference on Quantum, Nano and Micro Technologies (ICQNM)•Feb 1, 2009•0 citations

Extreme nonlocality with one photon

Libby Heaney, Adán Cabello, Marcelo França Santos +1 more

Quantum nonlocality is typically assigned to systems of two or more well-separated particles, but nonlocality can also exist in systems consisting of just a single particle when one considers the subsystems to be distant spatial field modes. Single particle nonlocality has been confirmed experimentally via a bipartite Bell inequality. In this paper, we introduce an N -party Hardy-like proof of the impossibility of local elements of reality and a Bell inequality for local realistic theories in the case of a single particle superposed symmetrically over N spatial field modes (i.e. N qubit W state). We show that, in the limit of large N , the Hardy-like proof effectively becomes an all-versus-nothing (or Greenberger–Horne–Zeilinger (GHZ)-like) proof, and the quantum-classical gap of the Bell inequality tends to be the same as that in a three-particle GHZ experiment. We describe how to test the nonlocality in realistic systems.

arXiv:0911.0770•New Journal of Physics•May 27, 2011•82 citations

Bell’s Theorem, and Beyond

Junghee Ryu

The inconsistency of local hidden variables with quantum physics fascinates many physicists. Even though Bell’s theorem was studied mostly in terms of statistical inequalities, Greenberger, Horne, and Zeilinger derived all-versus-nothing test for multiqubit system, which is more striking contradiction without inequalities. This article briefly introduces Anton Zeilinger’s journey toward the Bell’s theorem.

Physics and High Technology•Dec 28, 2022•0 citations
All experimental tests of Bell-type inequalities and Greenberger-Horne-Zeilinger setups rely on the separate and successive measurement of the terms involved. We discuss possibilities of experimental setups to measure all relevant terms simultaneously in a single experiment and find this to be impossible. One reason is the lack of multi-partite states which are unique in the sense that a measurement of some observable on one particle fixes the value of the corresponding observables of the other particles as well.
All experimental tests of Bell-type inequalities and Greenberger–Horne–Zeilinger setups rely on the separate and successive measurement of the terms involved. We discuss possibilities of experimental setups to measure all relevant terms simultaneously in a single experiment and find this to be impossible. One reason is the lack of multi-partite states which are unique in the sense that a measurement of some observable on one particle fixes the value of the corresponding observables of the other particles as well.
We present a general method for obtaining all Bell inequalities for a given experimental setup. Although the algorithm runs slowly, we apply it to two cases. First, the Greenberger-Horne-Zeilinger setup with three observers each performing one of two possible measurements. Second, the case of two observers each performing one of three possible experiments. In both cases we obtain hundreds of inequalities. Since this is the set of all inequalities, the one that is maximally violated in a given quantum state must be among them. We demonstrate this fact with a few examples. We also note the deep connection between the inequalities and classical logic, and their violation with quantum logic.
Quantum nonlocality is typically assigned to systems of two or more well-separated particles, but nonlocality can also exist in systems consisting of just a single particle when one considers the subsystems to be distant spatial field modes. Single particle nonlocality has been confirmed experimentally via a bipartite Bell inequality. In this paper, we introduce an N -party Hardy-like proof of the impossibility of local elements of reality and a Bell inequality for local realistic theories in the case of a single particle superposed symmetrically over N spatial field modes (i.e. N qubit W state). We show that, in the limit of large N , the Hardy-like proof effectively becomes an all-versus-nothing (or Greenberger–Horne–Zeilinger (GHZ)-like) proof, and the quantum-classical gap of the Bell inequality tends to be the same as that in a three-particle GHZ experiment. We describe how to test the nonlocality in realistic systems.