近日，中国科学技术大学潘建伟团队研究了可扩展量子中继器的长寿命远程离子-离子纠缠。相关论文于2026年2月2日发表在《自然》杂志上。

量子网络融合了量子通信、量子计量与分布式量子计算，有望实现安全高效的信息传输、高分辨率传感以及信息处理的指数级加速。实现长距离确定性纠缠分发是构建可扩展量子网络的先决条件。然而，光纤中光子损耗随距离呈指数增长，阻碍了高效且确定性的纠缠分发。量子中继器通过结合纠缠交换、纠缠纯化与量子存储器，为克服光纤量子网络中的这一限制提供了最具前景的解决方案。尽管已有诸多开创性研究，关键瓶颈依然存在：远程存储器-存储器纠缠会以快于长距离建立与纯化过程的速度发生退相干。

研究组首次演示了两个通过10公里卷绕光纤连接的节点之间建立的存储器-存储器纠缠，其持续时间超越了平均纠缠建立时间。这一突破得益于长寿命囚禁离子存储器、高效电信波段接口以及高可见度单光子纠缠协议的协同发展。作为应用展示，研究组实现了原理验证性的设备无关量子密钥分发实验，在10公里距离上完成有限长安全分析，并在渐进极限下实现了101公里距离的正密钥率——这两个距离均超过先前工作的两个数量级以上。该研究成果为量子中继器提供了关键构建模块，标志着向可扩展量子网络迈出了重要一步。

附：英文原文

Title: Long-lived remote ion-ion entanglement for scalable quantum repeaters

Author: Liu, Wen-Zhao, Zhou, Ya-Bin, Chen, Jiu-Peng, Wang, Bin, Teng, Ao, Han, Xiao-Wen, Liu, Guang-Cheng, Zhang, Zhi-Jiong, Yang, Yi, Liu, Feng-Guang, Xue, Chao-Hui, Yang, Bo-Wen, Yang, Jin, Zeng, Chao, Pan, Du-Ruo, Zheng, Ming-Yang, Zhang, Xingjian, Cao, Shen, Zhen, Yi-Zheng, Xiao, You, Li, Hao, You, Lixing, Ma, Xiongfeng, Zhao, Qi, Xu, Feihu, Wang, Ye, Wan, Yong, Zhang, Qiang, Pan, Jian-Wei

Issue&Volume: 2026-02-02

Abstract: Quantum networks, integrating quantum communication, quantum metrology, and distributed quantum computing, could provide secure and efficient information transfer, high-resolution sensing, and an exponential speed-up in information processing1. Deterministic entanglement distribution over long distances is a prerequisite for scalable quantum networks2–5. However, the exponential photon loss in optical fibres prohibits efficient and deterministic entanglement distribution. Quantum repeaters6, incorporating entanglement swapping4,7,8 and entanglement purification9–11 with quantum memories, offer the most promising means to overcome this limitation in fibre-based quantum networks. Despite numerous pioneering efforts12–25, a critical bottleneck remains, as remote memory-memory entanglement suffers from decoherence more rapidly than it can be established and purified over long distances. Here, we demonstrate memory-memory entanglement between two nodes connected by 10 km of spooled fibre surviving beyond the average entanglement establishment time. This is enabled by the development of long-lived trapped-ion memories, an efficient telecom interface, and a high-visibility single-photon entanglement protocol26,27. As an application, we report a proof-of-principle device-independent quantum key distributio (DI-QKD) demonstration with finite-size analysis over 10 km and a positive key rate over 101 km in the asymptotic limit, with both distances exceeding previous work by more than two orders of magnitude28–30. Our work provides a critical building block for quantum repeaters and marks an important step toward scalable quantum networks.

DOI: 10.1038/s41586-026-10177-4

Source: https://www.nature.com/articles/s41586-026-10177-4