(IFL.Science) Chinese scientists have unveiled the world’s first integrated quantum communication network made of 700 optical fibers stretching across 2,000 kilometers (1,200 miles) between Beijing and Shangai. Combined with China’s Quantum Satellite, the full network covers a distance of 4,600 kilometers (2,860 miles). Details of the network are reported in Nature.
Scientists have worked for several years on how to improve quantum key distribution (QKD). For the ground-based portions, they developed a new technology called Twin-Field QKD which allowed the transmission of keys four times further than previous records.
On the satellite-to-ground part of the network, the tests and improvements conducted over the last few years with the Micius satellite led them to produce a QKD of 47.8 kilobits per second, 40 times faster than their previous record. The team stresses that its channel loss is comparable to what is seen in actual geostationary satellites, so it could be possible in the future for the deployment of quantum satellites in geostationary orbit.
“Our work shows that quantum communication technology is sufficiently mature for large-scale practical applications,” a statement on the study says.
China is already planning to expand the network and collaborating with international partners in Austria, Italy, Russia, and Canada.