Fully connected quantum networks enable simultaneously connecting every user to every other user and are the most versatile and robust networking architecture. However, the scalability of such networks remains great challenge for practical applications. Here we construct a large-scale fully connected quantum network founded on two-photon Hong-Ou-Mandel (HOM) interference, where user-to-user security is guaranteed even with untrusted network provider. Using integrated soliton microcomb (SMC) and photonic encoding chips, we realize precise massive parallel frequency generation and locking, high-visibility HOM interferences and measurement-device-independent (MDI) quantum key distribution. The proposed architecture enables a 200-user fully connected quantum network over 200 kilometers with strict information-theoretic security via untrusted network provider. The implemented networking architecture paves the way for realizing large-scale fully connected MDI quantum networks across metropolitan and intercity regions.
Cite
@article{arxiv.2512.17318,
title = {Microcomb-driven large-scale fully connected quantum network},
author = {Fang-Xiang Wang and Sheng-Teng Zheng and Long Huang and Guo-We Zhang and Guang-Shu Wang and Wen-Jing Ding and Ze-Hao Wang and Shuang Wang and Zhen-Qiang Yin and Chang-Ling Zou and Brent E. Little and Guochao Wang and Lingxiao Zhu and Guang-Can Guo and Weiqiang Wang and Wenfu Zhang and Wei Chen and Zheng-Fu Han},
journal= {arXiv preprint arXiv:2512.17318},
year = {2025}
}