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arXiv · 2007.12727

Quantum key distribution with entangled photons generated on-demand by a quantum dot

Francesco Basso Basset·Mauro Valeri·Emanuele Roccia·Valerio Muredda·Davide Poderini·Julia Neuwirth·Nicolò Spagnolo·Michele B. Rota·Gonzalo Carvacho·Fabio Sciarrino·Rinaldo Trotta
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Abstract

Quantum key distribution---exchanging a random secret key relying on a quantum mechanical resource---is the core feature of secure quantum networks. Entanglement-based protocols offer additional layers of security and scale favorably with quantum repeaters, but the stringent requirements set on the photon source have made their use situational so far. Semiconductor-based quantum emitters are a promising solution in this scenario, ensuring on-demand generation of near-unity-fidelity entangled photons with record-low multi-photon emission, the latter feature countering some of the best eavesdropping attacks. Here we first employ a quantum dot to experimentally demonstrate a modified Ekert quantum key distribution protocol with two quantum channel approaches: both a 250 meter long single mode fiber and in free-space, connecting two buildings within the campus of Sapienza University in Rome. Our field study highlights that quantum-dot entangled-photon sources are ready to go beyond laboratory experiments, thus opening the way to real-life quantum communication.

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Francesco Basso Basset, Mauro Valeri, Emanuele Roccia, Valerio Muredda, Davide Poderini, Julia Neuwirth, Nicolò Spagnolo, Michele B. Rota, Gonzalo Carvacho, Fabio Sciarrino, Rinaldo Trotta. 2020-07-24. Quantum key distribution with entangled photons generated on-demand by a quantum dot. https://doi.org/10.1126/sciadv.abe6379

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