Practical repeaters for ultralong-distance quantum communication

Abstract

Quantum communication is at the forefront of quantum technology, enabling the development of absolutely secure encryption, distributed quantum computing, teleportation and more. Whilst quantum communication has been experimentally demonstrated at distances on the order of hundreds of kilometers, the establishment of high-fidelity pairs shared over larger distances remains a formidable technical challenge due to attenuation. However, this may be overcome with the use of quantum repeaters. Here we propose a method to construct a robust quantum repeater network using only existing technology. Our protocol is able to perform all parts of the procedure in a way that is highly tolerant to photon loss and imperfections in detectors, and it achieves secure bit rates on the order of kilohertz over intercontinental distances.