Gaussian Entanglement Distribution via Satellite

TL;DR

This paper compares three satellite-based quantum communication schemes for generating Gaussian entanglement between ground stations, analyzing the trade-offs between satellite complexity and entanglement rates under atmospheric turbulence.

Contribution

It introduces and compares three schemes for satellite-mediated Gaussian entanglement distribution, highlighting the impact of satellite complexity on entanglement rates.

Findings

Ground-based scheme achieves entanglement without satellite complexity.

Satellite-involved schemes can improve entanglement rates with added space-based quantum processing.

Trade-offs exist between engineering complexity and entanglement generation efficiency.

Abstract

In this work we analyse three quantum communication schemes for the generation of Gaussian entanglement between two ground stations. Communication occurs via a satellite over two independent atmospheric fading channels dominated by turbulence-induced beam wander. In our first scheme the engineering complexity remains largely on the ground transceivers, with the satellite acting simply as a reflector. Although the channel state information of the two atmospheric channels remains unknown in this scheme, the Gaussian entanglement generation between the ground stations can still be determined. On the ground, distillation and Gaussification procedures can be applied, leading to a refined Gaussian entanglement generation rate between the ground stations. We compare the rates produced by this first scheme with two competing schemes in which quantum complexity is added to the satellite, thereby illustrating the trade-off between space-based engineering complexity and the rate of ground-station entanglement generation.