Creation of memory-memory entanglement in a metropolitan quantum network

• 成果类型: Article
• 署名作者: Liu, Jian-Long; Luo, Xi-Yu; Yu, Yong; Wang, Chao-Yang; Wang, Bin; Hu, Yi; Li, Jun; Zheng, Ming-Yang; Yao, Bo; Yan, Zi; Teng, Da; Jiang, Jin-Wei; Liu, Xiao-Bing; Xie, Xiu-Ping; Zhang, Jun; Mao, Qing-He; Jiang, Xiao; Zhang, Qiang; Bao, Xiao-Hui; Pan, Jian-Wei
• 署名单位: Chinese Academy of Sciences; University of Science & Technology of China, CAS; Chinese Academy of Sciences; University of Science & Technology of China, CAS; CAS Center for Excellence in Quantum Information & Quantum Physics; Hefei National Laboratory; Chinese Academy of Sciences; University of Science & Technology of China, CAS; Chinese Academy of Sciences; Hefei Institutes of Physical Science, CAS; Chinese Academy of Sciences; University of Science & Technology of China, CAS; Delft University of Technology
• 刊物名称: Nature
• ISSN/ISSBN: 0028-6958
• DOI: 10.1038/s41586-024-07308-0
• 发表日期: 2024-05-16
• 页码: 579-+
• 关键词: heralded entanglement; atomic ensembles; COMMUNICATION; repeaters; nodes; qubit

摘要

Towards realizing the future quantum internet(1,2), a pivotal milestone entails the transition from two-node proof-of-principle experiments conducted in laboratories to comprehensive multi-node set-ups on large scales. Here we report the creation of memory-memory entanglement in a multi-node quantum network over a metropolitan area. We use three independent memory nodes, each of which is equipped with an atomic ensemble quantum memory(3) that has telecom conversion, together with a photonic server where detection of a single photon heralds the success of entanglement generation. The memory nodes are maximally separated apart for 12.5kilometres. We actively stabilize the phase variance owing to fibre links and control lasers. We demonstrate concurrent entanglement generation between any two memory nodes. The memory lifetime is longer than the round-trip communication time. Our work provides a metropolitan-scale testbed for the evaluation and exploration of multi-node quantum network protocols and starts a stage of quantum internet research.