The laws of physics do not prohibit counterfactual communication

TL;DR

This paper presents a counterfactual communication scheme that defies the conjecture of impossibility, demonstrating experimentally and theoretically that information can be transmitted without particles traveling between sender and receiver.

Contribution

It introduces a novel counterfactual communication protocol that is both experimentally verified and conceptually consistent, challenging previous assumptions about quantum communication limits.

Findings

Counterfactual communication is experimentally demonstrated.

Fidelity of information transfer can approach unity.

The scheme satisfies both experimental and conceptual criteria without loopholes.

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.