Unconditional quantum teleportational advantage of single photons

TL;DR

This paper demonstrates an all-optical scheme for quantum teleportation of single photons that surpasses direct transmission in efficiency, establishing an unconditional teleportational advantage despite significant photon loss.

Contribution

The authors propose and experimentally realize a scheme achieving teleportational advantage over direct transmission in photon survival probability.

Findings

Achieved 82% heralding efficiency for entangled photons.

Demonstrated 2.95-fold enhancement in transmission efficiency via teleportation.

Overcame previous limitations by establishing unconditional teleportational advantage.

Abstract

Photon loss is the biggest enemy in quantum communications. Direct transmission typically results in a small fraction of photons surviving over long distances, hindering advanced applications such as loophole-free Bell tests and device-independent quantum key distribution. Quantum teleportation offers a "disembodied" way of transferring particles through a virtual channel--quantum entanglement--which, in principle, could overcome the photon transmission loss. Experimentally, however, no previous quantum teleportation of single photons has shown a higher survival probability than using direct transmission. To overcome this challenge, here we first propose and demonstrate an all-optical scheme for remote preparation of entangled photons. Through an effective 15-dB channel loss, we realize a heralding efficiency of 82% for event-ready entangled photons. Based on the prior distributed entanglement, we demonstrate that teleportation-based transmission efficiency offers a 2.95-fold enhancement, compared to using direct transmission through the same channel, therefore establishing an unconditional teleportational advantage.