Quantum Leap: 254km Quantum Communication Achieved on Existing Infrastructure

Scientists in Germany have achieved a breakthrough in quantum communication, transmitting quantum messages over 254 kilometers of existing commercial fiber optic network. This is a world record, utilizing a coherence-based twin-field quantum key distribution protocol. The experiment successfully transmitted information between three data centers (Frankfurt, Kehl, and Kirchfeld) without needing cryogenic cooling, demonstrating the viability of advanced quantum communication protocols on pre-existing telecom infrastructure and paving the way for a quantum internet.