Quantum Messages Travel 254 km Using Existing Infrastructure For the First Time

Researchers in Germany successfully demonstrated coherent quantum communications over 254 km of existing commercial telecom fiber, marking the first real-world deployment of such a system without cryogenic cooling. Phys.Org reports: Their system uses a coherence-based twin-field quantum key distribution, which facilitates the distribution of secure information over long distances. The quantum communications network was deployed over three telecommunication data centers in Germany (Frankfurt, Kehl and Kirchfeld), connected by 254 km of commercial optical fiber -- a new record distance for real-world and practical quantum key distribution, according to the authors. This demonstration indicates that advanced quantum communications protocols that exploit the coherence of light can be made to work over existing telecom infrastructure. The research has been published in the journal Nature.

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