Entanglement's Benefit Survives an Entanglement-Breaking Channel

TL;DR

This paper demonstrates experimentally that entanglement-based communication remains secure and functional even through channels that would normally break entanglement, highlighting its practical robustness.

Contribution

It provides the first experimental evidence that entanglement-based protocols can withstand entanglement-breaking noise, enabling secure communication in realistic noisy environments.

Findings

Entanglement-based communication survives beyond entanglement-breaking thresholds.

Eavesdropping immunity is achieved with entangled sources under high noise.

Classical sources do not provide the same robustness.

Abstract

Entanglement is essential to many quantum information applications, but it is easily destroyed by quantum decoherence arising from interaction with the environment. We report the first experimental demonstration of an entanglement-based protocol that is resilient to loss and noise which destroy entanglement. Specifically, despite channel noise 8.3 dB beyond the threshold for entanglement breaking, eavesdropping-immune communication is achieved between Alice and Bob when an entangled source is used, but no such immunity is obtainable when their source is classical. The results prove that entanglement can be utilized beneficially in lossy and noisy situations, i.e., in practical scenarios.