Vinet Stéphane, Tannous Ramy, Jennewein Thomas
Institute for Quantum Computing and Department of Physics & Astronomy, University of Waterloo, 200 University Ave W, Waterloo, N2L 3G1 Ontario Canada.
Currently with the National Research Council of Canada, 100 Sussex Drive, Ottawa, K1A 0R6 Ontario Canada.
EPJ Quantum Technol. 2025;12(1):8. doi: 10.1140/epjqt/s40507-025-00305-w. Epub 2025 Jan 22.
Satellite-based quantum communication channels are important for ultra-long distances. Given the short duration of a satellite pass, it can be challenging to efficiently connect multiple users of a city-wide network while the satellite is passing over that area. We propose a network with dual-functionality: during a brief satellite pass, the ground network is configured as a multipoint-to-point topology where all ground nodes establish entanglement with a satellite receiver. During times when this satellite is not available, the satellite up-link is rerouted via a single optical switch to the ground nodes, and the network is configured as a pair-wise ground network. We numerically simulate a pulsed hyper-entangled photon source and study the performance of the proposed network configurations for quantum key distribution. We find favourable scaling in the case that the satellite receiver exploits time-multiplexing whereas the ground nodes utilize frequency-multiplexing. The scalability, simple reconfigurability, and easy integration with fibre networks make this architecture a promising candidate for quantum communication of many ground nodes and a satellite, an important step towards interconnection of ground nodes at a global scale.
基于卫星的量子通信信道对于超远距离通信很重要。鉴于卫星过境时间短暂，在卫星飞越城市区域时，高效连接城市范围网络的多个用户可能具有挑战性。我们提出一种具有双重功能的网络：在短暂的卫星过境期间，地面网络配置为多点到点拓扑结构，所有地面节点与卫星接收器建立纠缠。在卫星不可用时，卫星上行链路通过单个光开关重新路由到地面节点，网络配置为成对地面网络。我们对脉冲超纠缠光子源进行了数值模拟，并研究了所提出的网络配置用于量子密钥分发的性能。我们发现，在卫星接收器利用时分复用而地面节点利用频分复用的情况下，具有良好的扩展性。这种架构的可扩展性、简单的可重构性以及与光纤网络的易于集成，使其成为众多地面节点与卫星进行量子通信的有前途的候选方案，是迈向全球规模地面节点互连的重要一步。
