Entanglement-based quantum key distribution can enable secure communication in trusted node-free networks and over long distances. Although implementations exist both in fiber and in free space, the latter approach is often considered challenging due to environmental factors. Here, we implement a quantum communication protocol during daytime for the first time using a quantum dot source. This technology presents advantages in terms of narrower spectral bandwidth -- beneficial for filtering out sunlight -- and negligible multiphoton emission at peak brightness. We demonstrate continuous operation over the course of three and a half days, across an urban 270-m-long free-space optical link, under different light and weather conditions.
@article{arxiv.2206.15360,
title = {Daylight entanglement-based quantum key distribution with a quantum dot source},
author = {Francesco Basso Basset and Mauro Valeri and Julia Neuwirth and Emanuele Polino and Michele B. Rota and Davide Poderini and Claudio Pardo and Giovanni Rodari and Emanuele Roccia and Saimon F. Covre da Silva and Giuseppe Ronco and Nicolò Spagnolo and Armando Rastelli and Gonzalo Carvacho and Fabio Sciarrino and Rinaldo Trotta},
journal= {arXiv preprint arXiv:2206.15360},
year = {2022}
}
Comments
The first two authors contributed equally to this work. 10 pages, 3 figures