Creation of memory–memory entanglement in a metropolitan quantum network
Jian-Long Liu (University of Science and Technology of China)
Xi-Yu Luo (University of Science and Technology of China)
Yong Yu (University of Science and Technology of China, TU Delft - QN/Groeblacher Lab)
Chao-Yang Wang (University of Science and Technology of China)
Bin Wang (University of Science and Technology of China)
Yi Hu (University of Science and Technology of China)
Jun Li (University of Science and Technology of China)
Xiao-Hui Bao (University of Science and Technology of China)
Jian-Wei Pan (University of Science and Technology of China)
undefined More Authors
More Info
expand_more
Other than for strictly personal use, it is not permitted to download, forward or distribute the text or part of it, without the consent of the author(s) and/or copyright holder(s), unless the work is under an open content license such as Creative Commons.
Abstract
Towards realizing the future quantum internet, 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 memory3 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 12.5 kilometres. 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.