Chinese scientists achieve 300-km quantum direct communication breakthrough

Chinese scientists have successfully constructed a quantum-secure direct communication network covering approximately 300 kilometres, marking a significant advancement in inter-city quantum communication. This is reported by CGTN, a partner of TV BRICS.

The research demonstrates stable quantum information transfer with over 85 per cent fidelity between users. The system operates reliably even in noisy environments, offering a photon pair rate of 300–400 Hz – enough to support communication speeds of several bits per second.

This breakthrough addresses two core limitations in quantum communication: the expansion of transmission distance and scalability of user connections. The new system is fully connected, double-pumped, and designed for practical application beyond laboratory settings.

This achievement follows a previous milestone set earlier this year when researchers in Beijing achieved quantum direct communication over 104.8 kilometres using standard optical fibre.

In a separate demonstration, Chinese scientists led the first successful real-time quantum key distribution transmission over 12,900 km between China and South Africa using a satellite, marking a critical step toward building a global quantum internet.

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