论文标题
迈向大都市自由空间量子网络
Towards metropolitan free-space quantum networks
论文作者
论文摘要
量子通信在实用大规模网络方面取得了迅速的进步，量子密钥分布（QKD）率先为这一开发。尽管已经证明基于纤维的系统非常适合大都市尺度，但合适的纤维基础设施可能并不总是存在。在这里，我们为基于纠缠的自由空间量子网络作为大都市应用程序的实用且有效的替代方案。我们开发了可部署的自由空间QKD系统，并在现实的情况下展示了其使用。对于代表性的1.7公里自由空间链接，我们展示了其临时可部署性，并实现高达5.7 kbps的安全关键速度，并在直接中午的阳光下达到2.5 kbps。通过推断实验数据，我们表明KBPS关键率即使在10公里距离和多用户方案也可以达到。我们预计我们的工作将建立自由空间网络，作为大都市应用程序的可行解决方案，并且在未来的全球量子互联网中建立了必不可少的互补构建块。
Quantum communication has seen rapid progress towards practical large-scale networks, with quantum key distribution (QKD) spearheading this development. While fibre based systems have been shown to be well suited for metropolitan scales, suitable fibre infrastructure may not always be in place. Here, we make the case for an entanglement-based free-space quantum network as a practical and efficient alternative for metropolitan applications. We developed a deployable free space QKD system and demonstrated its use in realistic scenarios. For a representative 1.7-km free-space link, we showcase its ad hoc deployability and achieve secure key rates of up to 5.7 kbps, with 2.5 kbps in direct noon sunlight. By extrapolating experimental data, we show that kbps key rates are achievable even for 10-km distances and multi-user scenarios. We anticipate that our work will establish free space networks as a viable solution for metropolitan applications and an indispensable complementary building block in the future global quantum internet.
