One of the world’s most renowned scientific journals, Nature, has reviewed the results of three major quantum communication projects that appear to be pioneering to establish a “real” quantum internet in the future. These experiments, conducted by teams in the USA, China, and the Netherlands, are described as the most advanced demonstrations yet of quantum internet technology.

These research groups have successfully demonstrated quantum entanglement over several kilometres of existing optical fibres in urban areas, marking a significant milestone towards a future quantum internet. Quantum entanglement links objects so they contain the same information regardless of distance, enabling secure communication and potentially connecting quantum computers into more powerful systems. The Chinese team used rubidium atom clouds, the Dutch team used nitrogen atoms in diamond crystals, and the USA team used silicon atoms in diamond. These methods all overcame the challenge of maintaining entanglement over long distances in real-world conditions, moving the technology from the lab into practical urban environments. Although not yet commercially viable, this progress is a significant step toward realising a quantum internet.

Details and source of cover image:

Davide Castelvecchi: ‘Quantum internet’ demonstration in cities is most advanced yet. Nature 629, 734-735 (2024) https://doi.org/10.1038/d41586-024-01445-2