Free-space and Satellite-Based Quantum Communication: Principles, Implementations, and Challenges

TL;DR

This paper reviews the principles, implementations, and challenges of satellite-based quantum communication systems, highlighting recent advancements, technical hurdles, and future prospects for establishing secure, global quantum networks.

Contribution

It provides a comprehensive overview of satellite quantum communication technologies, including recent milestones and the challenges to achieving a global quantum internet.

Findings

Successful implementation of quantum communication via Micius satellite

Identification of atmospheric turbulence as a key challenge

Discussion of quantum repeaters for extending communication range

Abstract

Satellite-based quantum communications represent a critical advancement in the pursuit of secure, global-scale quantum networks. Leveraging the principles of quantum mechanics, these systems offer unparalleled security through Quantum Key Distribution (QKD) and other quantum communication protocols. This review provides a comprehensive overview of the current state of satellite-based quantum communications, focusing on the evolution from terrestrial to space-based systems. We explore the distinct advantages and challenges of discrete-variable (DV) and continuous-variable (CV) quantum communication technologies in the context of satellite deployments. The paper also discusses key milestones such as the successful implementation of quantum communication via the Micius satellite and outlines the primary challenges, including atmospheric turbulence and the development of quantum repeaters, that must be addressed to achieve a global quantum internet. This review aims to consolidate recent advancements in the field, providing insights and perspectives on the future directions and potential innovations that will drive the continued evolution of satellite-based quantum communications.