Entanglement routing with guaranteed fidelity for drone-based quantum networks

The quantum Internet is profoundly impacting the world and is expected to be operational in the future. With the global wide-area quantum networks begin to take shape, drone-based quantum entanglement networks have attracted widespread attention. Compared to quantum links based on optical fibers or satellites, drone-based quantum entanglement networks can effectively address the need for responsive and on-demand quantum network coverage across diverse locations and operational times. To realize network construction, entanglement routing protocols pose a significant challenge. On the one hand, the fidelity of the entangled system degrades hop-byhop. On the other hand, the dynamics and limited energy of drone nodes are equally not negligible. However, existing works have not adequately addressed these issues. In this paper, we present a novel fidelity-guaranteed entanglement routing protocol for drone-based quantum networks (FGER_D). The FGER_D considers the node energy and quantum link vulnerability comprehensively, selects end-to-end fidelity as the routing metric, and employs multiple attempts' entanglement purification scheme to provide fidelity-guaranteed entanglement connections in noisy environments. Numerical simulations demonstrate that compared to existing algorithms, FGER_D improves network throughput by approximately 24% under default settings, while also ensuring network fidelity and extending network lifetime. Our work is expected to provide a theoretical basis for the deployment of drone-based entanglement distribution networks.