Long-lived remote ion-ion entanglement for scalable quantum repeaters
TL;DR
Researchers demonstrate long-lived remote ion-ion entanglement over 10 km of fiber, enabling scalable quantum repeaters and a proof-of-principle device-independent quantum key distribution over distances exceeding previous work by orders of magnitude.
Key Takeaways
- •Long-lived trapped-ion memories and efficient telecom interfaces enable remote memory-memory entanglement to survive beyond the average establishment time over 10 km of fiber.
- •The demonstration supports a proof-of-principle device-independent quantum key distribution (DI-QKD) with positive key rates over 101 km in the asymptotic limit.
- •This work addresses a critical bottleneck in quantum networks by overcoming decoherence, marking a significant step toward scalable quantum repeaters and practical quantum communication.
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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.
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Author information
These authors contributed equally: Wen-Zhao Liu, Ya-Bin Zhou, Jiu-Peng Chen, Bin Wang
Authors and Affiliations
Hefei National Research Center for Physical Sciences at the Microscale and School of Physical Sciences, University of Science and Technology of China, Hefei, Anhui, China
Wen-Zhao Liu, Ya-Bin Zhou, Jiu-Peng Chen, Ao Teng, Xiao-Wen Han, Guang-Cheng Liu, Zhi-Jiong Zhang, Yi Yang, Feng-Guang Liu, Chao-Hui Xue, Bo-Wen Yang, Jin Yang, Chao Zeng, Yi-Zheng Zhen, Feihu Xu, Ye Wang, Yong Wan, Qiang Zhang & Jian-Wei Pan
Shanghai Research Center for Quantum Science and CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Shanghai, China
Wen-Zhao Liu, Ya-Bin Zhou, Jiu-Peng Chen, Ao Teng, Xiao-Wen Han, Guang-Cheng Liu, Zhi-Jiong Zhang, Yi Yang, Feng-Guang Liu, Chao-Hui Xue, Bo-Wen Yang, Jin Yang, Chao Zeng, Du-Ruo Pan, Yi-Zheng Zhen, Feihu Xu, Ye Wang, Yong Wan, Qiang Zhang & Jian-Wei Pan
Hefei National Laboratory, University of Science and Technology of China, Hefei, China
Wen-Zhao Liu, Ya-Bin Zhou, Jiu-Peng Chen, Bin Wang, Ao Teng, Xiao-Wen Han, Guang-Cheng Liu, Zhi-Jiong Zhang, Yi Yang, Feng-Guang Liu, Chao-Hui Xue, Bo-Wen Yang, Jin Yang, Chao Zeng, Ming-Yang Zheng, Yi-Zheng Zhen, Xiongfeng Ma, Feihu Xu, Ye Wang, Yong Wan, Qiang Zhang & Jian-Wei Pan
Jinan Institute of Quantum Technology, Jinan, China
Bin Wang, Yi Yang, Ming-Yang Zheng & Qiang Zhang
Department of Physics, Anhui Normal University, Wuhu, Anhui, China
Jin Yang
QICI Quantum Information and Computation Initiative, School of Computing and Data Science, The University of Hong Kong, Hong Kong SAR, China
Xingjian Zhang, Shen Cao & Qi Zhao
National Key Laboratory of Materials for Integrated Circuits, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences (SIMIT, CAS), Shanghai, China
You Xiao, Hao Li & Lixing You
Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing, China
Xiongfeng Ma
- Wen-Zhao Liu
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- Ya-Bin Zhou
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- Jiu-Peng Chen
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- Bin Wang
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- Ao Teng
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- Xiao-Wen Han
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- Zhi-Jiong Zhang
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