Journal Article

Metropolitan-scale ion-photon entanglement via a quantum network node with hybrid multiplexing enhancements

Sun, Y.-D., Xu, Y., Liu, P.-Y., Cui, Z.-B., Duan, L.-M., Qi, B.-X., Pu, Y.-F., Lai, P.-C., Huang, Y.-Y., Zhou, Z.-C., Shi, J.-X., Wang, Z.-Q., Wang, Y., Liang, Y.-B., Wu, Y.-K., Tian, Z.-C.

2025

Overview

Quantum network and quantum repeater are promising ways to scale up a quantum information system. In a functional quantum network, it is required that the distribution rate of heralded remote entanglement should be higher than the decoherence rate of each local node. A promising scheme to accelerate the remote entanglement distribution is through multiplexing enhancement. In this work, we experimentally realize a multiplexed quantum network node based on a chain of 40 Ca + ions. We employ a hybrid multiplexing scheme in which maximally 44 time-bin modes are generated and sent through a long fiber to boost the entangling rate. Via this scheme, we can generate heralded ion-photon entanglement with a success rate of 4.28 s −1 over a 12 km fiber. In addition, a dual-type framework is utilized to protect quantum information from the destructive ion-photon entangling attempts and a memory coherence time of 366 ms is achieved, which has exceeded the entanglement generation time. Despite recent advances with trappedion-based platforms, achieving quantum networks with link efficiency greater than unity on metropolitan scales is still a challenge. Here, the authors demonstrate a multiplexed quantum network generating heralded entanglement at a rate faster than local decoherence.

• Publisher: Nature Publishing Group UK,Nature Publishing Group,Nature Portfolio
• Subject: 639/766/400/3925 / 639/766/400/482 / 639/766/483/3925 / 639/766/483/481 / Calcium isotopes / Communication / Cooling / Efficiency / Humanities and Social Sciences / Long fibers / multidisciplinary / Multiplexing / Nodes / Photons / Quantum entanglement / Quantum phenomena / Science / Science (multidisciplinary) / Travel