Global-scale quantum networking using hybrid-channel quantum repeaters with relays based on a chain of balloons

TL;DR

This paper proposes a global quantum network using balloon-based aerial relays optimized to reduce atmospheric disturbances, achieving high-efficiency entanglement distribution over 10,000 km, surpassing satellite-based methods.

Contribution

It introduces a novel hybrid-channel quantum repeater scheme with balloon relays and demonstrates optimized atmospheric disturbance mitigation for long-distance quantum communication.

Findings

Achieves -21 dB channel efficiency over 10,000 km

Outperforms satellite relays by 12 dB with same device parameters

Demonstrates sub-Hertz entanglement distribution rate over global distances

Abstract

Global-scale entanglement distribution has been a formidable challenge due to the unavoidable losses in communication channels. Here, we propose a novel backbone channel for quantum network based on balloon-based aerial relays. We demonstrate for the first time that the atmospheric disturbances in balloon-based channels can be almost eliminated through optimizing beam waist positions and employing a series of adaptive optics systems, which boosts the channel efficiency to -21 dB over a 10,000 km distance, outperforming satellite-based relays by 12 dB with same device parameters. We then propose a global-scale quantum networking scheme based on hybrid-channel quantum repeaters that combine ground-based quantum repeaters and balloon-based aerial relays. Servers are interconnected globally via a chain of balloons, while clients link to local servers through fiber connections, facilitating rapid client switching and network scalability. Our simulations, employing state-of-the-art Eu$^{3+}$:Y$_2$SiO$_5$ quantum memories and mature entanglement sources based on spontaneous parametric down-conversion, demonstrate an entanglement distribution rate in the sub-Hertz range between clients separated by 10,000 km. This approach offers a practical path toward global quantum networking in the near future.