Quantum teleportation could enable faster data transfers
Before Star Trek fans go berserk, we have to state it’s not the same teleportation as in the sci-fi series. Scientists in China have succeeded in teleporting information between photons further than ever before. They transported quantum information over a free space distance of 16 km (10 miles), much further than the few hundred meters previously achieved, which brings us closer to transmitting information over long distances without the need for a traditional signal.
As we previously stated. quantum teleportation is not the same as the teleportation most of us know from science fiction, where an object (or person) in one place is “beamed up” to another place where a perfect copy is replicated. In quantum teleportation two photons or ions (for example) are connected in such a way that when the quantum state of one is changed the state of the other also changes, as if the two were still connected. This enables quantum information to be sent (teleported) if the state of one of the photons or ions is altered.
In previous experiments the photons were confined to fiber channels a few hundred meters long to ensure their state remained unchanged, but in the new experiments pairs of photons were entangled and then the higher-energy photon of the pair was sent through a free space channel 16 km long. The researchers, from the University of Science and Technology of China and Tsinghua University in Beijing, found that even at this distance the photon at the receiving end still responded to changes in state of the photon remaining behind. The average fidelity of the teleportation achieved was 89 percent.
The achieved distance is greater than the effective aerosphere thickness of 5-10 km (3-6.5 miles), so the group’s success could pave the way for experiments between a ground station and a satellite, or two ground stations with a satellite acting as a relay. This means quantum communication applications could be possible on a global scale in the future.
The public free space channel was at ground level and spanned the 16 km distance between Badaling in Beijing (the teleportation site) and the receiver site at Huailai in Hebei province. Photon pairs were generated at the teleportation site using a semiconductor, a blue laser beam, and a crystal of beta-barium borate (BBO). The pairs of photons were entangled in the spatial modes of photon 1 and polarization modes of photon 2. The research team designed two types of telescopes to serve as optical transmitting and receiving antennas.
The experiments confirm the feasibility of space-based quantum teleportation, and represent a giant leap forward in the development of quantum communication applications. Though their experiment is impressive, there’s still a long way to go before information can safely be sent this way. Photons are good at transmitting information, but ions are better at allowing manipulation, which would be necessary for encryption and eventual transportation of matter in its original form. For more information, check the paper they published: Experimental free-space quantum teleportation.