‘Quantum teleportation’ breakthrough for 'Qauntum Internet'
Physicists have set a new bar for quantum teleportation, moving information from one place to another without physically sending anything between the locations.Two separate teams funded by Darpa, managed to teleport information across several kilometers of optical fibre network in two cities. This form of teleportation involves transferring quantum states of a light particles.
Teleportation over long distances and across optical fibre networks, is an important step towards the future of internet, and ultra-secure communications promised by quantum cryptography.
The process by which information the quantum state of a photon is teleported, involves creating two photons at the University of Calgary (site B in the aerial photo below).
One of these photons is sent in a "classical" way along 11.1km of optical fibre to a building near Calgary City Hall, (site C in the photo), while the other remains behind at the university.
Meanwhile, a photon is also sent to the City Hall site from site A, located in the neighborhood of Manchester. This all results in the quantum state of the photon from site A being transferred to the photon which remained behind at the university, through quantum teleportation.
This teleportation process occurs via a phenomenon known as entanglement, which describes how sub-atomic particles can be linked even if they are separated by a large distance.
The details of entanglement are not well understood, even by Einstein in the past, who famously described it as "spooky action at a distance".
Dr Tittel says his study uses a configuration that could serve as the benchmark for useful city-based quantum networks. In the future, theoretical devices known as repeaters could help amplify signals, enabling communications - a quantum internet, over much bigger distances.
DARPA say that "photons are a valuable resource for many military applications ranging from communications systems to visible and infrared sensing platforms."
This could enable the roll-out of much more secure communications offered by quantum cryptography.
That would involve separate parties producing a shared and random secret key known only to them, that could be used to encrypt and decrypt messages.
"The broad availability of advanced communications technology possessed by adversaries makes it increasingly difficult to ensure the integrity and confidentiality of DoD information," the defense researcher explains.
The biggest application of quantum teleportation is likely to be in encrypting information. As the two photons communicate with each other via quantum entanglement, it is much harder for an outsider to read the information.
In order to decrypt a message, a hacker would need both the key - which is sent over the regular internet - and the entangled photons themselves.
Sources: RT, BBC
