Austrian physicists have been able to make the quantum teleportation of a record distance of 143 km. This experiment is an important step towards the establishment of a satellite system of quantum communication. Results of the study will be published in the journal Nature.
An international team, led by physicist Anton Zeilinger has successfully transmitted quantum state between two Canary Islands, located at a distance of 143 km from each other. The previous record was 97 km and was established by scientists in China a few months ago.
But it is not a record distance was the main objective of researchers. This experiment will lay the foundation for the global information network based on quantum-mechanical effects, which not only increase the security of messages, but also significantly speed up certain types of computations, as compared to conventional technologies. In this future ’quantum internet’, quantum teleportation will be a key transmission protocol information between quantum computers.
Xiao-song Ma, who took part in this experiment, said: "The implementation of quantum teleportation over a distance of 143 km, was a major technological challenge." Photons have to go through the turbulent atmosphere between the two islands. Optical fiber is not suitable for teleportation at such great distances, as the level of attenuation is too high. To achieve this goal, scientists were forced to implement a series of technological innovations.
"Our experiment showed how advanced quantum technologies today, and what benefits they can bring in a practical sense," - said Anton Zeilinger. "The next step will be to satellite quantum teleportation, which will make the reality of quantum communication on a global scale. We made a big step in that direction, and we will apply our know-how in international tests, which will be attended by our colleagues from China. Goal is to run "Quantum of satellite communications."
Rupert Ursin, who worked with Zeilinger, added: "The satellites in low-Earth orbit are located at an altitude of 200 to 1200 km above the Earth’s surface (ISS, for example, lies at an altitude of 400 km.) Walking the path between the two Canary Islands, the signal is attenuated by about a thousand times. Nevertheless, we were able to teleport. in satellite experiments, the distance will be longer, but the signal will go through a much more rarefied atmosphere. "