Toshiba Europe, GÉANT, PSNC and Anglia Ruskin University announce the first demonstration of quantum key distribution within commercial telecommunication networks

As reported in Nature, GÉANT, Toshiba Europe limited, PSNC and Anglia Ruskin University came together to work on the first major in-the-field demonstration of practical quantum communications using telecoms standard equipment and infrastructure.

The experiment was conducted in Germany, with access to the network infrastructure provided by GÉANT. Communication was established over a link spanning 253.9 km between Frankfurt and Kehl with a 56.0 dB loss and a relay in Kirchfeld, approximately three-fifths of the way. This setup forms a star-shaped quantum network with three nodes: two transmitters, at the network’s edge, and a central relay receiver.

Employing the Twin Field Quantum Key Distribution protocol, a key distribution rate of 110 bit/s over 254 km was achieved.

Importantly, this system features measurement-device-independent properties and non-cryogenically cooled detectors, and represents the first effective quantum repeater implementation on telecom infrastructure, the longest practical quantum key distribution deployment to date, and validates the feasibility of a phase-based quantum internet architecture.

This study marks the first successful integration of coherent quantum communications within a commercial telecom infrastructure outside of dedicated metro systems.

This article was first published on 24 April by GÉANT.