Perfection is achieved, not when there is nothing to add,
and when there is nothing to remove.

Antoine de Saint-exupéry

Chinese researchers demonstrated the first Intercontinental quantum communication channel

4 Oct 2017

Bai Chunli (Chunli Bai), President of the Chinese Academy of Sciences, and President of the Academy of Sciences of Austria Anton Zeilinger (Anton Zeilinger) on Friday last week held a video conference. During this conference, Bai Chunli was in Beijing, Anton Zeilinger in Vienna. But the most interesting in this case is that the videoconference was produced by entangled on a quantum level photons, "teleportion" halfway around the world Chinese experimental quantum communication satellite called Micius.

Note that the demonstration of quantum communications of distant radius of action was carried out after only a few weeks after the start of quantum communication networks, created on the basis of fiber-optic lines, with a length of 1 995 km connecting Beijing and Shanghai, and intended for use by Chinese military, government and financial institutions. In may this year, Chinese researchers announced the development of its own version of a quantum computer, which, according to them, operates in 24 thousands of times faster than computers of similar competing projects.

We remind our readers that the satellite Micius., named after an ancient Chinese scholar and philosopher, was launched into space in August 2016. On Board the satellite, flying at an altitude of 500 kilometers from the Earth's surface, is a quantum transmitter, quantum "teleportation" receiver, a source of entangled photons and the analyzer of optical signals.

Micius the satellite can transmit signals anywhere in the covered region, using the phenomenon of quantum entanglement, i.e. creating a pair of photons having interconnected quantum state. One of the entangled photons transmitted over long distances and using quantum "bridge" connecting these two photons, transmitted information cannot be intercepted or decrypted without knowledge of the secret key. In this case, for data transmission used photons entangled in their polarization.

Previously, the range of quantum optical communication through an open space does not exceed 200 kilometers from the harmful influence of the atmosphere on photons, which through some time and distance lose their state of entanglement. In this case, the problem was solved due to the fact that most of the time the photons of light travel through the void of outer space.

"Exchange of information that is encrypted at the quantum level, at Intercontinental distances, confirms the huge potential of quantum communication technologies," says Anton Zeilinger, "all this is very important step towards creating a global and secure quantum Internet."