14 DAY TRIAL // A recent paper announces a teleportation breakthrough. Thus, specialists with the University of Geneva in Switzerland claim to have teleported the quantum state of a photon to a crystal over a distance of 25 kilometers (15.5 miles).
The experiment, carried out with the help of optical fiber, breaks the previous record of 6 kilometers (3.7 miles) set by the same team of researchers back in 2003, and is hailed as a world first.
Quantum teleportation explained
Thanks to Hollywood and sci-fi books, many think of teleportation as moving objects like an apple, an animal and maybe even a human from one place to another without having to traverse the physical space between the point of origin and the final destination.
Quantum teleportation is about transportation, but it's not about locking bunnies in a cupboard on one continent and have them appear at the other end of the world. On the contrary, it's about transporting quantum information, i.e. the exact state of an atom or a photon, using classical communication.
The University of Geneva experiments
In their paper, the scientists behind this latest experiment in quantum teleportation explain that what they did was use optical fiber to teleport the quantum state of a photon over 25 kilometers (15.5 miles) to a crystal.
Essentially, they had the crystal become a memory bank for the photon's information, and proved that the state of a particle could be maintained in environments that are as different one from the other as light is from matter. Even simpler, they transited information from light to matter over a record distance.
“Passing from light into matter, using teleportation of a photon to a crystal, shows that, in quantum physics, it is not the composition of a particle which is important, but rather its state, since this can exist and persist outside such extreme differences as those which distinguish light from matter.”
“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,” Science Daily explains the work of Professor Nicolas Gisin and colleagues.
Toying with quantum entanglement
As part of this research project, the University of Geneva scientists started by selecting two photons entangled in a quantum state. Such photons are inextricably linked and, even if located at a distance, respond to outside influences like joined twins.
Of these photons, one was propelled along 25 kilometers (15.5 miles) of optical fiber, and another was sent to the crystal. Then, a third photon was added to the mix, and made to travel along the optical fiber, where it eventually collided with the first entangled photon. Following this collision, the information in the third photon was not destroyed, but instead worked its way to the crystal, where the entangled photon's twin sat.
“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,” researcher Félix Bussières explains the outcome of this experiment.
A detailed account of this research project is available in the journal Nature Photonics. The paper is titled “Reduced spin measurement back-action for a phase sensitivity ten times beyond the standard quantum limit.”