Direct and full-scale experimental verifications towards ground-satellite quantum key distribution

TL;DR

This paper reports on three independent experiments demonstrating the feasibility of ground-satellite quantum key distribution (QKD) under various challenging conditions, advancing towards global quantum communication networks.

Contribution

It provides the first full-scale experimental verification of ground-satellite QKD using a decoy-state system in moving and high-loss scenarios, simulating real satellite conditions.

Findings

Successful QKD over large distances with moving platforms

Demonstrated system robustness under vibration and attitude changes

Achieved high-loss regime performance

Abstract

Quantum key distribution (QKD), provides the only intrinsically unconditional secure method for communication based on principle of quantum mechanics. Compared with fiber-based demonstrations-, free-space links could provide the most appealing solution for much larger distance. Despite of significant efforts, so far all realizations rely on stationary sites. Justifications are therefore extremely crucial for applications via a typical Low Earth Orbit Satellite (LEOS). To achieve direct and full-scale verifications, we demonstrate here three independent experiments with a decoy-state QKD system overcoming all the demanding conditions. The system is operated in a moving platform through a turntable, a floating platform through a hot-air balloon, and a huge loss channel, respectively, for substantiating performances under rapid motion, attitude change, vibration, random movement of satellites and in high-loss regime. The experiments cover expanded ranges for all the leading parameters of LEOS. Our results pave the way towards ground-satellite QKD and global quantum communication network.