Quantum information teleportation over 16 km of free space channel
Scientists from the University of Science and Technology of China, in Hefei, and from Tsinghua Universtiy, in Beijing, have succeeded to transport quantum information over a free space distance of 16 km, from a source at Badaling in Beijing to a destination in Huailai in Hebei province (see map below).
Quantum information teleportation is not the same thing as teleportation that we see in science fiction, where an object is beamed up from one place to another. In quantum information teleportation, two photons are entangled in such a way that when the quantum state of one is changed, the state of the other also changes, as if the two are still connected. This enables quantum information to be teleported if one of the photons is sent some distance away.
Previous experiments of quantum information teleportation were performed on fiber channels over a few hundred meters long. In this new experiment, pairs of photos are entangled and the higher-energy one is sent through free space (empty space, or the atmosphere) over a distance of 16 km.
This success could pave the way for experiments between a ground station and a satellite, or between ground stations using satellite as relay.
Quantum information teleportation would allow for instantaneous communication, much faster than the current fiber optic-based communication infrastructure.
The article is published on Nature and can be found here.