# Inter-satellite Quantum Key Distribution at Terahertz Frequencies

## TL;DR

This paper investigates the feasibility of using terahertz frequencies for quantum key distribution among micro-satellites and ground stations, proposing a new approach for space-based quantum communication networks.

## Contribution

It demonstrates the viability of THz quantum entanglement and key distribution in satellite constellations, enabling simpler integration of global quantum and wireless networks.

## Key findings

- THz quantum entanglement distribution is feasible in LEO satellites.
- THz quantum key distribution can be implemented between satellites and ground stations.
- Potential for THz-based quantum-radar applications in space is discussed.

## Abstract

Terahertz (THz) communication is a topic of much research in the context of high-capacity next-generation wireless networks. Quantum communication is also a topic of intensive research, most recently in the context of space-based deployments. In this work we explore the use of THz frequencies as a means to achieve quantum communication within a constellation of micro-satellites in Low-Earth-Orbit (LEO). Quantum communication between the micro-satellite constellation and high-altitude terrestrial stations is also investigated. Our work demonstrates that THz quantum entanglement distribution and THz quantum key distribution are viable deployment options in the micro-satellite context. We discuss how such deployment opens up the possibility for simpler integration of global quantum and wireless networks. The possibility of using THz frequencies for quantum-radar applications in the context of LEO deployments is briefly discussed.