Experimental quantum teleportation over a high-loss free-space channel

TL;DR

This paper demonstrates high-fidelity quantum teleportation over a high-loss free-space channel, achieving results relevant for satellite-based quantum communication and advancing global quantum networks.

Contribution

It reports the first high-fidelity quantum teleportation over a high-loss free-space channel with practical implications for satellite communication.

Findings

Achieved an average fidelity of 0.82 beyond the classical limit.

Successfully reconstructed process matrices of quantum teleportation.

Addressed technical challenges for future satellite-based quantum experiments.

Abstract

We present a high-fidelity quantum teleportation experiment over a high-loss free-space channel between two laboratories. We teleported six states of three mutually unbiased bases and obtained an average state fidelity of 0.82(1), well beyond the classical limit of 2/3. With the obtained data, we tomographically reconstructed the process matrices of quantum teleportation. The free-space channel attenuation of 31 dB corresponds to the estimated attenuation regime for a down-link from a low-earth-orbit satellite to a ground station. We also discussed various important technical issues for future experiments, including the dark counts of single-photon detectors, coincidence-window width etc. Our experiment tested the limit of performing quantum teleportation with state-of-the-art resources. It is an important step towards future satellite-based quantum teleportation and paves the way for establishing a worldwide quantum communication network.