Quantum teleportation involves the exchange of information in the form of quantum states, not matter, between two points with the use of quantum entanglement. In principle, the distances can be arbitrarily long and works even if the location of the recipient is not known. Cryptography is a key element in quantum communications and quantum computers. It takes advantage of quantum entanglement, the phenomenon in which two objects, such as photons, are connected in such a way, even at great distances, that changing the state of one instantly changes the state of the other. If an eavesdropper intercepts the message, this entangled state is disrupted and the aggression is thus noticed.
The latest article in a recent series of breakthroughs in quantum teleportation involves researchers at the Niels Bohr Institute who have reported in Nature Physics (1) that they have succeeded in teleporting information between two clouds of gas atoms, and they have done so every single time they attempted. The experiment involves two glass containers, each containing caesium gas atoms. Information is teleported from one glass container to the other by means of a laser beam of light which becomes entangled with the gas atoms. Even though the glass containers were only a half meter apart, it “is entirely due to the size of the laboratory,” explains Eugene Polzik. “We could increase the range if we had the space and, in principle, we could teleport information, for example, to a satellite.” (2)
Anton Zeilinger’s group in Vienna have succeeded in teleporting information over long distances. In a paper in Nature in 2012 (3), an international team led by Zeilinger reported successfully transmitting quantum states over a distance of 143 kilometers, between two Canary Islands.