2026-04-21 ニューヨーク大学（NYU）
A New York City quantum network connecting NYU and QTD Systems in Manhattan with Brooklyn’s Qunnect. The image depicts the distribution of secure communications using entangled photons in an experiment that shows the viability of long-distance communication.
＜関連情報＞
- https://www.nyu.edu/about/news-publications/news/2026/april/scientists-take-a-step-toward-a-quantum-internet-using-new-york-.html
- https://arxiv.org/abs/2602.15653
- https://arxiv.org/pdf/2602.15653
ニューヨーク市に展開された光ファイバー上で、遠隔の量子もつれ源間で高速かつスケーラブルな量子もつれ交換を実現する
High-rate Scalable Entanglement Swapping Between Remote Entanglement Sources on Deployed New York City Fibers
Alexander N. Craddock, Tyler Cowan, Niccolò Bigagli, Suresh Yekasiri, Dylan Robinson, Gabriel Bello Portmann, Aditya Verma, Ziyu Guo, Michael Kilzer, Jiapeng Zhao, Mael Flament, Javad Shabani, Reza Nejabati, Mehdi Namazi
arXiv last revised 2 Mar 2026 (this version, v2)
DOI:https://doi.org/10.48550/arXiv.2602.15653
Entanglement swapping between photon pairs generated at physically separated nodes over telecommunication fiber infrastructure is an essential step towards the quantum internet, enabling applications such as quantum repeaters, blind quantum computing, distributed quantum computing, and distributed quantum sensing. However, successful networked entanglement swapping relies on generating indistinguishable pairs of photons and preserving them over deployed fibers. This has limited most previous demonstrations to laboratory settings or relied on sophisticated methods to maintain the necessary indistinguishability. Here, we demonstrate a scalable entanglement swapping experiment using naturally indistinguishable entanglement sources based on warm atomic vapor cells. Without sharing lasers or optical frequency references between nodes, nor the need for pulsing the sources, we achieve a swapping rate of nearly 500 pairs/s while maintaining the CHSH parameter above 2. Additionally, we demonstrate the scalability of our method by maintaining the quality of the entanglement swapping on 17.6-km of deployed fibers in NYC, relying on commercially available SPADs at the spoke nodes, SNSPDs at the hub and standard time-synchronization techniques. Our work paves the way for the practical deployment of large-scale hub-and-spoke quantum networks within cities and data centers.
