Free-space quantum key distribution to a moving receiver

TL;DR

This paper demonstrates a pioneering free-space quantum key distribution system from a stationary transmitter to a moving receiver, simulating satellite communication conditions and achieving secure key generation despite dynamic challenges.

Contribution

It introduces a novel free-space QKD setup to a moving platform, overcoming beam pointing, polarization, and timing challenges, simulating satellite-to-ground quantum communication.

Findings

Secure key rate of 40 bits/sec achieved

Successfully corrected beam pointing and polarization in motion

Simulated satellite communication conditions

Abstract

Technological realities limit terrestrial quantum key distribution (QKD) to single-link distances of a few hundred kilometers. One promising avenue for global-scale quantum communication networks is to use low-Earth-orbit satellites. Here we report the first demonstration of QKD from a stationary transmitter to a receiver platform traveling at an angular speed equivalent to a 600 km altitude satellite, located on a moving truck. We overcome the challenges of actively correcting beam pointing, photon polarization and time-of-flight. Our system generates an asymptotic secure key at 40 bits/s.