Physicists at the University of Vienna and the Austrian Academy of Sciences have achieved quantum teleportation over a record distance of 143 km. The experiment is a major step towards satellite-based quantum communication. The results have now been published in Nature.
An international team led by the Austrian physicist Anton Zeilinger has successfully transmitted quantum states between the two Canary Islands of La Palma and Tenerife, over a distance of 143 km. The previous record, set by researchers in China just a few months ago, was 97 km.
Breaking the distance record wasn’t the scientists’ primary goal though. This experiment provides the basis for a worldwide information network, in which quantum mechanical effects enable the exchange of messages with greater security, and allow certain calculations to be performed more efficiently than with conventional technologies. In such a future ‘quantum internet’, quantum teleportation will be a key protocol for the transmission of information between quantum computers.
In a quantum teleportation experiment, quantum states—but not matter—are exchanged between two parties over distances that can be, in principle, arbitrarily long. The process works even if the location of the recipient is not known. Such an exchange can be used either for the transmission of messages, or as an operation in future quantum computers. In these applications the photons that encode the quantum states have to be transported reliably over long distances without compromising the fragile quantum state. The experiment of the Austrian physicists, in which they have now set up a quantum connection suitable for quantum teleportation over distances of more than 100 km, opens up new horizons. Via 143 km: Physicists break quantum teleportation distance.