Some rather exciting news today. A team of scientists in China announced that they’ve been able to extend the distance that a photon’s state was able to be instantly teleported to just about 10 miles (16km).
The idea behind quantum teleportation is that you take two entangled state objects (like a pair of electrons, or in this case a pair of photons) and then make use of the non-classical behavior of entanglement which means that changes to one object instantly modify the other. (Instantly is faster than the speed of light…) So this is really more about the creation of something like sub-space radio from Star Trek than it is the Teleporter that Mr. Scott used so artistically.
From the report on the methodology used:
“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 distance of 16 km is greater than the effective aerosphere thickness of 5-10 km, 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 near 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. Entangled 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.”
Read the full article here.
This will have some interesting immediate application in quantum computing and, if the distance can be extended, information transmission.
Neat. Another macroscopic manifestation of Entanglement.
