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Entangling metropolitan-distance separated quantum memories
Version 2 2023-06-08, 12:52
Version 1 2023-01-12, 14:58
preprintposted on 2023-06-08, 12:52 authored by Xi-Yu Luo, Yong Yu, Jian-Long Liu, Ming-Yang Zheng, Chao-Yang Wang, Bin Wang, Jun Li, Xiao Jiang, Xiu-Ping Xie, Qiang Zhang, Xiao-Hui Bao, Jian-Wei Pan
Quantum internet gives the promise of getting all quantum resources connected, and it will enable applications far beyond a localized scenario. A prototype is a network of quantum memories that are entangled and well separated. Previous realizations are limited in the distance. In this paper, we report the establishment of remote entanglement between two atomic quantum memories physically separated by 12.5 km directly in a metropolitan area. We create atom-photon entanglement in one node and send the photon to a second node for storage. We harness low-loss transmission through a field-deployed fiber of 20.5 km by making use of frequency down-conversion and up-conversion. The final memory-memory entanglement is verified to have a fidelity of 90% via retrieving to photons. Our experiment paves the way to study quantum network applications in a practical scenario.