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arXiv · 2110.01480

Photonic verification of device-independent quantum key distribution against collective attacks

Wen-Zhao Liu·Yu-Zhe Zhang·Yi-Zheng Zhen·Ming-Han Li·Yang Liu·Jingyun Fan·Feihu Xu·Qiang Zhang·Jian-Wei Pan
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Abstract

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.

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Wen-Zhao Liu, Yu-Zhe Zhang, Yi-Zheng Zhen, Ming-Han Li, Yang Liu, Jingyun Fan, Feihu Xu, Qiang Zhang, Jian-Wei Pan. 2021-10-04. Photonic verification of device-independent quantum key distribution against collective attacks. https://doi.org/10.1103/physrevlett.129.050502

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