C. Varnava , R. M. Stevenson , J. Nilsson , J. Skiba-Szymanska , B. Dzurňák , M. Lucamarini , R. V. Penty , I. Farrer , D. A. Ritchie , A. J. Shields
2015-06-01
Quantum cryptography allows confidential information to be communicated between two parties, with secrecy guaranteed by the laws of nature alone. However, upholding guaranteed secrecy over quantum communication networks poses a further challenge, as classical receive-and-resend routing nodes can only be used conditional of trust by the communicating parties. Here, we demonstrate the operation of a quantum relay over 1 km of optical fiber, which teleports a sequence of photonic quantum bits to a receiver by utilizing entangled photons emitted by a semiconductor LED. The average relay fidelity of the link is 0.90+/-0.03, exceeding the classical bound of 0.75 for the set of states used, and sufficiently high to allow error correction. The fundamentally low multi-photon emission statistics and the integration potential of the source present an appealing platform for future quantum networks.
http://arxiv.org/licenses/nonexclusive-distrib/1.0/