Satellite-Terrestrial Quantum Networks and the Global Quantum Internet

TL;DR

This paper proposes a three-layer satellite-terrestrial quantum network architecture integrating GEO and LEO satellites with ground stations, analyzing channel conditions and highlighting LEO satellites' role in entanglement distribution for the future quantum internet.

Contribution

It introduces a novel three-layer design for space-terrestrial quantum networks, detailing the roles of GEO and LEO satellites and analyzing channel conditions for entanglement distribution.

Findings

LEO satellites are key for entanglement distribution.

GEO satellites coordinate and manage the network.

The design considers near-term applications without quantum memory.

Abstract

This paper will explore the design and implementation of quantum networks in space integrated with quantum networks on Earth. We propose a three-layer approach, involving GEO and LEO satellites integrated with terrestrial ground stations. We first analyze the channel conditions between the three layers, and then highlight the key role of LEO satellites in the integrated space-terrestrial system - namely the source of entanglement distribution between specified terrestrial stations via direct downlink quantum-optical channels. The GEO satellites in the considered system are used primarily as coordination stations, managing and directing the LEO satellites regarding the positioning and timing of entanglement distribution. Complexity, in the form of entanglement distillation and quantum-state correction, is concentrated at the terrestrial stations, and teleportation is used as the primary quantum channel in the LEO uplinks and the inter-terrestrial channels. Although our designs are futuristic in that they assume limited quantum memory at the transceivers, we also discuss some near-term uses of our network in which no quantum memory is available.