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Enhanced violations of Leggett-Garg inequalities in an experimental three-level system

Lookup NU author(s): Dr Clive Emary



This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License (CC BY-NC 4.0).


Leggett-Garg inequalities are tests of macroscopic realism that can be violated by quantum mechanics. In this letter, we realise photonic Leggett-Garg tests on a three-level system and implement measurements that admit three distinct measurement outcomes, rather than the usual two. In this way we obtain violations of three- and four-time Leggett-Garg inequalities that are significantly in excess of those obtainable in standard Leggett-Garg tests. We also report violations the quantum-witness equality up to the maximum permitted for a three-outcome measurement. Our results highlight differences between spatial and temporal correlations in quantum mechanics.

Publication metadata

Author(s): Wang K, Emary C, Zhan X, Bian Z, Li J, Xue P

Publication type: Article

Publication status: Published

Journal: Optics Express

Year: 2017

Volume: 25

Issue: 25

Pages: 31462-31470

Print publication date: 11/12/2017

Online publication date: 04/12/2017

Acceptance date: 22/11/2017

Date deposited: 06/12/2017

ISSN (electronic): 1094-4087

Publisher: Optical Society of America


DOI: 10.1364/OE.25.031462


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