A reconfigurable entanglement distribution network suitable for connecting multiple ground nodes with a satellite

TL;DR

This paper proposes a reconfigurable satellite-ground quantum network architecture that adapts between multipoint and pair-wise configurations, enabling scalable, efficient quantum communication with multiple ground nodes and a satellite.

Contribution

It introduces a dual-functionality quantum network design that switches between multipoint and pair-wise configurations, enhancing scalability and reconfigurability for satellite-based quantum communication.

Findings

Favorable scaling with time-multiplexed satellite receiver and frequency-multiplexed ground nodes.

Simple reconfigurability and integration with fibre networks.

Potential for global-scale quantum ground-satellite interconnection.

Abstract

Satellite-based quantum communication channels are important for ultra-long distances. Given the short duration of a satellite pass, it can be challenging to efficiently connect multiple users of a city-wide network while the satellite is passing over that area. We propose a network with dual-functionality: during a brief satellite pass, the ground network is configured as a multipoint-to-point topology where all ground nodes establish entanglement with a satellite receiver. During times when this satellite is not available, the satellite up-link is rerouted via a single optical switch to the ground nodes, and the network is configured as a pair-wise ground network. We numerically simulate a pulsed hyper-entangled photon source and study the performance of the proposed network configurations for quantum key distribution. We find favourable scaling in the case that the satellite receiver exploits time-multiplexing whereas the ground nodes utilize frequency-multiplexing. The scalability, simple reconfigurability, and easy integration with fibre networks make this architecture a promising candidate for quantum communication of many ground nodes and a satellite, thus paving the way towards interconnection of ground nodes at a global scale.