Quantum key distribution with an entangled light emitting diode
Branislav Dzurňák, R. M. Stevenson, Johan S. Nilsson, J. F. Dynes, Zhiliang L. Yuan, J. Skiba-Szymanska, Ian A. Farrer, D. A. Ritchie, Andrew J. Shields · Applied Physics Letters · 2015
Measurements performed on entangled photon pairs shared between two parties can allow unique quantum cryptographic keys to be formed, creating secure links between users. An advantage of using such entangled photon links is that they can be adapted to propagate entanglement to end users of quantum networks with only untrusted nodes. However, demonstrations of quantum key distribution with entangled photons have so far relied on sources optically excited with lasers. Here, we realize a quantum cryptography system based on an electrically driven entangled-light-emitting diode. Measurement bases are passively chosen and we show formation of an error-free quantum key. Our measurements also simultaneously reveal Bell's parameter for the detected light, which exceeds the threshold for quantum entanglement.