Towards a function-scalable quantum network with multiplexed energy-time entanglement
Abstract
Quantum networks, which hinge on the principles of quantum mechanics, are revolutionizing the domain of information technology. The vision for quantum networks involves the efficient distribution and utilization of quantum resources across a network to support a variety of quantum applications. However, current quantum protocols often develop independently, leading to incompatibilities that limit the functional scalability of the network. In this paper, we showcase a compatible and complementary implementation of two distinct quantum applications, quantum time synchronization and quantum cryptography, by multiplexing the same energy-time entangled biphotons and quantum channel. A proof-of-principle experiment between two independent nodes across a 120 km fiber-optic link is demonstrated, which achieve sub-picosecond synchronization stability based on the quantum two-way time transfer protocol. Simultaneously, this synchronization provides the required timing for implementing dispersive-optic quantum key distribution with an average finite-size secure key rate of 73.8 bits per second, which can be employed to safeguard the security of the transferred timing data. Furthermore, thanks to the compatibility, potential asymmetric delay attacks in the link, which are detrimental to the accomplishment of secure key distribution, can be effectively mitigated by the parallel quantum time synchronization procedure. Our demonstration marks a substantial leap towards unlocking the full potential of energy-time entanglement and paves the way for a resource-efficient, function-scalable, and highly compatible quantum network.
Cite
@article{arxiv.2502.08423,
title = {Towards a function-scalable quantum network with multiplexed energy-time entanglement},
author = {Xiao Xiang and Jingyuan Liu and Bingke Shi and Huibo Hong and Xizi Sun and Yuting Liu and Runai Quan and Tao Liu and Shougang Zhang and Wei Zhang and Ruifang Dong},
journal= {arXiv preprint arXiv:2502.08423},
year = {2025}
}