In this paper, we employ theoretical and experimental efforts and realize a proof-of-principle verification of device-independent QKD based on the photonic setup. On the theoretical side, we enhance the loss tolerance for real device imperfections by combining different approaches, namely, random post-selection, noisy preprocessing, and developed numerical methods to estimate the key rate via the von Neumann entropy. On the experimental side, we develop a high-quality polarization-entangled photon source achieving a state-of-the-art (heralded) detection efficiency about 87.5%. This efficiency outperforms previous photonic experiments involving loophole-free Bell tests. Together, we show that the measured quantum correlations are strong enough to ensure a positive key rate under the fiber length up to 220 m. Our photonic platform can generate entangled photons at a high rate and in the telecom wavelength, which is desirable for high-speed generation over long distances. The results present an important step towards a full demonstration of photonic device-independent QKD.
@article{arxiv.2110.01480,
title = {Photonic verification of device-independent quantum key distribution against collective attacks},
author = {Wen-Zhao Liu and Yu-Zhe Zhang and Yi-Zheng Zhen and Ming-Han Li and Yang Liu and Jingyun Fan and Feihu Xu and Qiang Zhang and Jian-Wei Pan},
journal= {arXiv preprint arXiv:2110.01480},
year = {2022}
}