Quantum networks and quantum repeaters represent the promising avenues for building large-scale quantum information systems, serving as foundational infrastructure for distributed quantum computing, long-distance quantum communication, and networked quantum sensing. A critical step in realizing a functional quantum network is the efficient and high-fidelity establishment of heralded entanglement between remote quantum nodes. Multiplexing offers a powerful strategy to accelerate remote entanglement distribution, particularly over long optical fibers. Here, we demonstrate the first multiplexing-enhanced heralded entanglement between two trapped-ion quantum network nodes. By multiplexing 10 temporal photonic modes, we achieve a 4.59-fold speedup in ion-ion entanglement generation and attain an entanglement fidelity of 95.9±1.5% over 1.2 km of fiber. Employing a dual-type architecture, our system is readily scalable to multiple nodes, thereby establishing a key building block for future large-scale quantum networks.
@article{arxiv.2510.20392,
title = {Multiplexed ion-ion entanglement over $1.2$ kilometer fibers},
author = {Z. B. Cui and Z. Q. Wang and P. Y. Liu and Y. Wang and P. C. Lai and J. X. Shi and Y. D. Sun and Z. C. Tian and H. S. Sun and Y. B. Liang and B. X. Qi and Y. Y. Huang and Z. C. Zhou and Y. K. Wu and Y. Xu and Y. F. Pu and L. M. Duan},
journal= {arXiv preprint arXiv:2510.20392},
year = {2025}
}