Device-independent quantum key distribution over 100 km with single atoms

• 成果类型: Article
• 署名作者: Lu, Bo-Wei; Yang, Chao-Wei; Wang, Run-Qi; Gao, Bo-Feng; Zhen, Yi-Zheng; Wang, Zhen-Gang; Shi, Jia-Kai; Ren, Zhong-Qi; Hahn, Thomas A.; Tan, Ernest Y. -Z.; Xie, Xiu-Ping; Zheng, Ming-Yang; Jiang, Xiao; Zhang, Jun; Xu, Feihu; 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; Chinese Academy of Sciences; University of Science & Technology of China, CAS; CAS Center for Excellence in Quantum Information & Quantum Physics; Chinese Academy of Sciences; Hefei National Laboratory; University of Science & Technology of China, CAS; Weizmann Institute of Science; University of Waterloo; University of Waterloo; National University of Singapore
• 刊物名称: SCIENCE
• ISSN/ISSBN: 0036-8075; 1095-9203
• DOI: 10.1126/science.aec6243
• 发表日期: 2026-02-05
• 关键词: ENTANGLEMENT PURIFICATION; DISTILLATION; creation

摘要

Device-independent quantum key distribution (DI-QKD) is a key application of the quantum internet. We report the realization of DI-QKD between two single-atom nodes linked by 100-kilometer (km) fibers. To improve the entangling rate, single-photon interference is leveraged for entanglement heralding, and quantum frequency conversion is used to reduce fiber loss. A tailored Rydberg-based emission scheme suppresses the photon recoil effect on the atom without introducing noise. We achieved high-fidelity atom-atom entanglement and positive asymptotic key rates for fiber lengths up to 100 km. At 11 km, 1.2 million heralded Bell pairs were prepared over 624 hours, yielding an estimated extractable finite-size secure key rate of 0.112 bits per event against general attacks. Our results close the gap between proof-of-principle quantum network experiments and real-world applications.