Simulating quantum repeater strategies for multiple satellites

TL;DR

This paper introduces a large-scale Monte Carlo simulation framework to evaluate quantum repeater networks involving multiple satellites, demonstrating feasible key rates for intercontinental quantum communication.

Contribution

It develops a comprehensive simulation scheme for satellite-based quantum repeaters, enabling analysis of complex multi-satellite configurations and strategies.

Findings

Key rates of a few kHz are achievable over intercontinental distances with three satellites.

The simulation can model loss and imperfections in multi-satellite quantum networks.

Various strategies and parameters can be explored using the developed toolbox.

Abstract

A global quantum repeater network involving satellite-based links is likely to have advantages over fiber-based networks in terms of long-distance communication, since the photon losses in free space scale only polynomially with the distance -- compared to the exponential losses in optical fibers. To simulate the performance of such networks, we have introduced a scheme of large-scale event-based Monte Carlo simulation of quantum repeaters with multiple memories that can faithfully represent loss and imperfections in these memories. In this work, we identify the quantum key distribution rates achievable in various satellite and ground station geometries for feasible experimental parameters. The power and flexibility of the simulation toolbox allows us to explore various strategies and parameters, some of which only arise in these more complex, multi-satellite repeater scenarios. As a primary result, we conclude that key rates in the kHz range are reasonably attainable for intercontinental quantum communication with three satellites, only one of which carries a quantum memory.