The laws of physics do not prohibit counterfactual communication

Abstract It has been conjectured that counterfactual communication is impossible, even for post-selected quantum particles. We strongly challenge this by proposing precisely such a counterfactual scheme where—unambiguously—none of Alice’s photons that correctly contribute to her information about Bo...

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Bibliographic Details
Main Authors: Hatim Salih, Will McCutcheon, Jonte R. Hance, John Rarity
Format: Article
Language:English
Published: Nature Portfolio 2022-05-01
Series:npj Quantum Information
Online Access:https://doi.org/10.1038/s41534-022-00564-w
Description
Summary:Abstract It has been conjectured that counterfactual communication is impossible, even for post-selected quantum particles. We strongly challenge this by proposing precisely such a counterfactual scheme where—unambiguously—none of Alice’s photons that correctly contribute to her information about Bob’s message have been to Bob. We demonstrate counterfactuality experimentally by means of weak measurements, and conceptually using consistent histories—thus simultaneously satisfying both criteria without loopholes. Importantly, the fidelity of Alice learning Bob’s bit can be made arbitrarily close to unity.
ISSN:2056-6387