Global-scale quantum communication links are essential for the quantum internet, but exponential loss in optical fibers limits their range. Quantum repeaters and space-based systems offer solutions. This paper analyzes using quantum memory (QM)-equipped satellites for quantum communication, focusing on global-range repeaters and memory-assisted (MA-) QKD. The authors demonstrate that QM-equipped satellites offer significantly faster entanglement distribution rates than existing protocols. They analyze how performance depends on memory characteristics, propose architectures for light-matter interfaces, and provide a roadmap for realizing unconditionally secure global quantum communications with near-term technologies.

Mustafa Gündoğan, Jasminder S. Sidhu, Victoria Henderson, Luca Mazzarella, Janik Wolters, Daniel K. L. Oi, Markus Krutzik