近日，中国科学技术大学李传锋团队报道了具有贝尔非局域性的城域规模多路复用量子中继器。相关论文于2026年5月7日发表在《自然—光子学》杂志上。

量子中继器能够克服光纤中的指数级光子损耗，从而实现远距离量子存储器之间的预示式纠缠。贝尔非定域性是衡量这一纠缠的最终基准；然而，近期基于单光子干涉方案的城域规模演示仅能产生低质量纠缠，尚无法达到贝尔非定域性认证的要求。

研究组介绍了一种基于时间测量的复用量子中继器协议，成功地将单光子干涉方案的高预示率与双光子干涉方案的相位鲁棒性结合起来。该方法在创纪录的14.5公里距离上，实现了两个固态量子存储器之间的预示式纠缠分发，所产生的贝尔态保真度达到78.6% ± 2.0%。研究组观测到Clauser-Horne-Shimony-Holt贝尔不等式的违背达3.7个标准差，这标志着城域规模量子中继器中贝尔非定域性的首次认证。该架构支持无需光纤通道相位稳定的自主量子节点操作，为可扩展的量子中继器网络提供了一个实用框架。

附：英文原文

Title: A metropolitan-scale multiplexed quantum repeater with Bell non-locality

Author: Zhu, Tian-Xiang, Zhang, Chao, Ou, Zhong-Wen, Liu, Xiao, Liang, Peng-Jun, Hu, Xiao-Min, Huang, Yun-Feng, Zhou, Zong-Quan, Li, Chuan-Feng, Guo, Guang-Can

Issue&Volume: 2026-05-07

Abstract: Quantum repeaters can overcome exponential photon loss in optical fibres, enabling heralded entanglement between distant quantum memories. The definitive benchmark for this entanglement is Bell non-locality; however, recent metropolitan-scale demonstrations based on single-photon interference schemes have been limited to generating low-quality entanglement, falling short of Bell non-locality certification. Here we introduce a multiplexed quantum repeater protocol based on time measurements, successfully combining the high heralding rate of single-photon interference schemes with the phase robustness of two-photon interference schemes. This approach achieves heralded entanglement distribution between two solid-state quantum memories over a record 14.5-km separation, generating a Bell state with a fidelity of 78.6% ± 2.0%. We observe a Clauser–Horne–Shimony–Holt–Bell inequality violation by 3.7 standard deviations, marking the first certification of Bell non-locality in metropolitan-scale quantum repeaters. Our architecture supports autonomous quantum node operation without fibre channel phase stabilization, offering a practical framework for scalable quantum repeater networks.

DOI: 10.1038/s41566-026-01911-5

Source: https://www.nature.com/articles/s41566-026-01911-5