Satellite-assisted quantum communication with single photon sources and atomic memories

TL;DR

This paper proposes a satellite-based quantum repeater architecture using atomic qubits as quantum memories and photon sources, enabling high-rate, long-distance entanglement distribution without cryogenic cooling.

Contribution

It introduces a novel satellite quantum repeater design with atomic qubits, offering deterministic Bell measurements and long coherence times in space.

Findings

High-fidelity entanglement over thousands of kilometers at 100 Hz rate

Fewer memory modes needed compared to conventional architectures

Achieves long-distance quantum communication without cryogenic technology

Abstract

Satellite-based quantum repeaters are a promising means to reach global distances in quantum networking due to the polynomial decrease of optical transmission with distance in free space, in contrast to the exponential decrease in optical fibers. We propose a satellite-based quantum repeater architecture with trapped individual atomic qubits, which can serve both as quantum memories and true single photon sources. This hardware allows for nearly deterministic Bell measurements and exhibits long coherence times without the need for costly cryogenic technology in space. We develop a detailed analytical model of the repeater, which includes the main imperfections of the quantum hardware and the optical link, allowing us to estimate that high-rate and high-fidelity entanglement distribution can be achieved over inter-continental distances. In particular, we find that high fidelity entanglement distribution over thousands of kilometres at a rate of 100 Hz can be achieved with orders of magnitude fewer memory modes than conventional architectures based on optical Bell state measurements.