Nature: Chinese Satellite Is One Giant Step for the Quantum Internet
CAS. Jul 28, 2016. China is poised to launch the world’s first satellite designed to do quantum experiments. A fleet of quantum-enabled craft is likely to follow.
First up could be more Chinese satellites, which will together create a super-secure communications network, potentially linking people anywhere in the world. But groups from Canada, Japan, Italy and Singapore also have plans for quantum space experiments.
“Definitely, I think there will be a race,” says Chaoyang Lu, a physicist at the -University of Science and Technology of China in Hefei, who works with the team behind the Chinese satellite. The 600-kilogram craft, the latest in a string of Chinese space-science satellites, will launch from Jiuquan Satellite Launch Center in August. The Chinese Academy of Sciences and the Austrian Academy of Sciences are collaborators on the US$100-million mission.
Quantum communications are secure because any tinkering with them is detectable. Two parties can communicate secretly — by sharing a encryption key encoded in the polarization of a string of photons, say — safe in the knowledge that any eavesdropping would leave its mark.
So far, scientists have managed to demonstrate quantum communication up to about 300 kilometres. Photons travelling through optical fibres and the air get scattered or absorbed, and amplifying a signal while preserving a photon’s fragile quantum state is extremely difficult. The Chinese researchers hope that transmitting photons through space, where they travel more smoothly, will allow them to communicate over greater distances.
For more details, please refer to NATURE: Chinese satellite is one giant step for the quantum internet.