Although it's not the same as teleportation in the science fiction sense (there's no "beam me up, Scotty, here), quantum teleportation still remains a breakthrough in physics. Now, a group of physicists from the University of Geneva (UNIGE) have broken the record for quantum teleportation, successfully transporting light particles along a 25 kilometer-long optical fiber into the matter particles of a crystal.
The previous record for quantum teleportation distance, in general, is 143 kilometers. That occurred last year, but that experiment only teleported light particles into other light particles.
This new experiment, though, teleported light particles into matter particles over a distance of 25 kilometers, and the previous record for that was only 6 kilometers. That record was also achieved by UNIGE over ten years ago.
"The latest experiments have enabled verifying that the quantum state of a photon can be maintained whilst transporting it into a crystal without the two coming directly into contact," says the team. "One needs to imagine the crystal as a memory bank for storing the photon's information; the latter is transferred over these distances using the teleportation effect."
Quantum teleportation happens when quantum information is transmitted from one location to another. In order for particles to teleport, they must reach something called superposition, which happens when particles exist in different forms all at the same time.
The UNIGE team took an identical pair of light particles, called photons, and entangled them, so that they existed in a quantum state. Physicists sent one of these particles along the length of a 25-kilometer optical fiber, while the other was sent to a crystal. Physicists blasted a third photon into the first, creating a collision which collapsed the quantum state and destroyed both particles.
After measuring the aftereffects of the collision, though, the team of physicists noticed that the third photon's information remained behind and was actually sent to the crystal, where the second entangled photon resided.
"The quantum state of the two elements of light, these two entangled photons which are like two Siamese twins, is a channel that empowers the teleportation from light into matter," says Felix Bussieres, the lead author of the study.
It may not seem like important research, but quantum teleportation is of interest to cryptographers. In the future, quantum particles could carry more data than today's computers, and that information would be impossible to decode or crack because any contact with the entangled pairs of particles would destroy the information they contain.
