HEFEI, Jan. 9 (Xinhua) -- Chinese scientists have set up an integrated quantum network that combines 700 fiber and two ground-to-satellite links and realized quantum key distribution between more than 150 users over a combined distance of 4,600 km.
So what does this mean? And how significant is it?
32 years ago, the first quantum communication in human history was created in a laboratory, which transmitted 32 cm.
Now Chinese scientists have expanded this distance by more than 14 million times, realizing multi-user communication from the ground to the space.
China launched the world's first quantum satellite in August 2016. It is nicknamed "Micius" after an ancient Chinese philosopher who's credited as the first to conduct optical experiments.
"Micius" has done major scientific tasks of quantum key distribution, quantum entanglement distribution and quantum teleportation.
Quantum key communicator. Through this machine, scientists have realized ground-to-satellite quantum key distribution.
Quantum experiment controller and processor.
It's like the "brain" of the quantum satellite, and it assures the accuracy of the ground-to-satellite quantum key distribution.
Quantum entanglement emitter. It can be used to conduct quantum entanglement distribution experiments over a distance.
This technology has helped achieve multi-user quantum key distribution over a span of 4,600 kilometers.
Based on the laws of quantum physics, quantum communications have ultra-high security.
It is impossible to wiretap, intercept or crack the information, since the quantum state of a photon that transmits data along optical fibers will "collapse" once it is wiretapped.
