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arXiv · 2306.06564

Guarding Quantum Key Distribution with integrated Magnetic-free Nonreciprocal Structures

Qiang Liu·Yinming Huang·Tingting Luo·Chunfeng Huang·Minming Geng·Zhenrong Zhang·Kejin Wei
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Abstract

Inserting nonreciprocal devices at the doorways of Alice and Bob is a widely recognized countermeasure against quantum hacking attacks in quantum key distribution (QKD) systems. However, traditional integrated nonreciprocal devices, which are typically based on magneto-optical effects, face challenges in compatibility with current semiconductor integration technology. As a result, earlier chip-based QKD systems were unable to integrate nonreciprocal components and were vulnerable to injecting-type attacks. Based on the actual parameters of SOI integration, we employed the inverse design with the direct binary search algorithm to construct several magnetic-free nonreciprocal devices, facilitating their integration into chip-based QKD systems while meeting various chip configuration design requirements. The designed devices have sizes of only a few square micrometers, yet the quasi-isolator can achieve an isolation level exceeding 27 dB. To demonstrate their practical utility in QKD, we employed the designed devices to safeguard the QKD system against Trojan-horse attacks. The simulation results demonstrate that our proposed devices effectively secure the BB84 and measure-device-independent QKD systems against Trojan-horse attacks.

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Qiang Liu, Yinming Huang, Tingting Luo, Chunfeng Huang, Minming Geng, Zhenrong Zhang, Kejin Wei. 2023-06-11. Guarding Quantum Key Distribution with integrated Magnetic-free Nonreciprocal Structures. https://arxiv.org/abs/2306.06564

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