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arXiv · 2503.07198

Entanglement distribution over metropolitan fiber using an on-chip broadband polarization entangled photon source

Zi-Heng Jiang·Yikai Chen·Wenhan Yan·Chi Lu·Wenjun Wen·Yu-Yang An·Leizhen Chen·Yuchen Liu·Hua-Ying Liu·Zhenda Xie·Yan-Qing Lu·Shining Zhu·Xiao-Song Ma
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Abstract

Entangled photon pairs are of crucial importance in quantum networks. For the future demands of large-scale and secure quantum communication, integrated photon sources are highly effective solutions. Here, we report entanglement distribution over a 30 km metropolitan area using on-chip broadband silicon nanowire biphoton polarization entangled source based on a silicon-on-insulator (SOI) platform. This source generates a continuous spectrum spanning the entire C-band (4.5 THz), achieving a locally detected coincidence counts of about 154 kHz within 100 GHz bandwidth, making it suitable for long-distance entanglement distribution among multiple users. By combining this source with quantum entanglement, enhanced by high-precision clock synchronization that achieves a standard deviation of 56.8 ps over 600 s, we observe a violation of the CHSH inequality by 27.8 standard deviations. Our results showcase the potential of silicon photonic technology as a scalable and practical platform for quantum technologies.

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Zi-Heng Jiang, Yikai Chen, Wenhan Yan, Chi Lu, Wenjun Wen, Yu-Yang An, Leizhen Chen, Yuchen Liu, Hua-Ying Liu, Zhenda Xie, Yan-Qing Lu, Shining Zhu, Xiao-Song Ma. 2025-03-10. Entanglement distribution over metropolitan fiber using an on-chip broadband polarization entangled photon source. https://doi.org/10.1103/5c5v-cw8c

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