May 13, 2012
Photons Teleported 60 Miles By Chinese Researchers
A team of Chinese physicists have shattered the record for quantum teleportation, teleporting photons approximately six times further than the previous best, according to various news reports published Friday.
A team of physicists hailing from the University of Science and Technology of China in Shanghai were able to teleport particles more than 97 kilometers, or over 60 miles, said Popular Science's Dan Nosowitz.
That smashes the prior standard of more than 10 miles (16-plus kilometers), which had been set by the same team back in 2010, Forbes Staff Writer Alex Knapp added.
Describing their research in a paper posted online, lead researcher Juan Yin and colleagues wrote, "Here, based on an ultra-bright multi-photon entanglement source, we demonstrate quantum teleportation, closely following the original scheme, for any unknown state created outside, between two optical free-space links separated by 97 km."
"Over a 35-53 dB high-loss quantum channel, an average fidelity of 80.4(9) % is achieved for six distinct initial states. Besides being of fundamental interest, our result represents an important step towards a global quantum network. Moreover, the high-frequency and high-accuracy acquiring, pointing and tracking (APT) technique developed in our experiment can be directly utilized for future satellite-based quantum communication," they added.
Teleportation, explained the Technology Review, which is published by the Massachusetts Institute of Technology (MIT), is the ability to transfer an object from one place to another without having to travel through the area between the two locations.
"The idea is not that the physical object is teleported but the information that describes it. This can then be applied to a similar object in a new location which effectively takes on the new identity," they said. "And it is by no means science fiction. Physicists have been teleporting photons since 1997 and the technique is now standard in optics laboratories all over the world."
"The phenomenon that makes this possible is known as quantum entanglement, the deep and mysterious link that occurs when two quantum objects share the same existence and yet are separated in space," the Technology Review added. "Teleportation turns out to be extremely useful. Because teleported information does not travel through the intervening space, it cannot be secretly accessed by an eavesdropper."
As a result of that property, teleportation is being adapted into a method of transmitting information in almost complete secrecy -- a method known as quantum cryptography. However, the MIT experts point out that the fragility of the photons used in the process means that they can only travel about one kilometer down optical fibers, limiting the usefulness of this form of cryptography.
"Quantum teleportation isn´t quite the same thing as the teleportation in Star Trek," Knapp pointed out. "When researchers teleport a photon, they aren´t teleporting the actual photon, but rather the information contained in it through quantum entanglement. In essence, the second photon at the end of the teleport becomes the first one -- or at least, it becomes an identical qubit of information. So the information is exchanged without actually travelling through the intervening distance."