Year: 2025
Type: preprint
Abstract: Quantum repeaters can overcome exponential photon loss in optical fibers, enabling heralded entanglement between distant quantum memories. The definitive benchmark for this entanglement is Bell nonlocality; however, recent metropolitan-scale demonstrations based on single-photon interference (SPI) schemes have been limited to generating low-quality entanglement, falling short of Bell nonlocality certification. Here, we introduce a multiplexed quantum repeater protocol based on time measurements (MQR-TM), successfully combining the high heralding rate of SPI schemes with the phase robustness of two-photon interference (TPI) schemes. This approach achieves heralded entanglement distribution between two solid-state quantum memories over a record 14.5~km separation, generating a Bell state with a fidelity of $78.6 \pm 2.0\%$. We observe a CHSH-Bell inequality violation by 3.7 standard deviations, marking the first certification of Bell nonlocality in metropolitan-scale quantum repeaters. Our architecture supports autonomous quantum node operation without fiber channel phase stabilization, offering a practical framework for scalable quantum-repeater networks.
Source: arXiv (Cornell University)
Authors: Zhu, Tian-Xiang, Zhang, Chao, Ou, Zhong-Wen, Liu, Xiao, Liang, Peng-Jun, Hu, Xiao-Min, Huang, Yun-Feng, Zhou, Zong-Quan, Li, Chuan-Feng, Guo, Guang-Can
Language: English
Subfield: Artificial Intelligence
Field: Computer Science
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7077974273
Cites:
Cited by:
Related to: