Quantum teleportation over fibre optic networks has the potential to greatly improve the security and strength of internet connections.
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Although the use of the word “teleportation” immediately conjures up images of Star Trek-like transporters – thanks to the theme being gratuitously exploited by science fiction books, shows and movies over the ages – quantum teleportation refers to the instantaneous transmission of information, rather than actual matter.
Two independent teams have transferred quantum information over several kilometres of fibre optic networks.
But today, an increasing body of evidence has confirmed the most counterintuitive predictions of quantum theory, including the unusual behaviour of “entangled” particles.
The difference between the particles at B and C is measured, revealing the change in the quantum state of point A.
Conceptually, one way of doing teleportation involves three participants: say, Alice, Bob and Charlie.
First Alice sends a particle (A) to Charlie.
A third photon encoded with information is then sent to the City Hall building from a third location to meet the second photon resulting in the data from the third photon being transferred to the first photon at the university due to its state of entanglement to the second.
Wolfgang Tittel and colleagues conducted their test in Calgary, Canada, but used photons at both a telecommunication wavelength and a wavelength of 795 nm, which allowed their quantum teleportation experiment to run faster than Zhang, Pan and colleagues’ experiment, but at a reduced fidelity.
Scientists have been playing around with the concept and testing it out in labs.
To overcome this, the research groups independently developed several feedback and synchronisation mechanisms to enable their teleportation experiments. Then in 2012, the record was set at over 143 kilometers (88.8 miles), when the teleportation happened between two particles in two separate locations in the Canary Islands.
But some deemed it to be impossible.
“We’re happy that part of our fibre infrastructure can be used by these fellows to be able to research cutting-edge technology”, Mayer said.
To decrypt any message, a separately sent key is required which, even if intercepted, would require the person to also have possession of the entangled photons.
Tittel said the team had to create feedback mechanisms in the experimental setup to ensure “very precise timing” of the photons’ arrivals at city hall, as small changes in outdoor temperature that cause the fibre-optic cables to expand or contract by minuscule amounts could throw off the timing. Crucially, the original particle loses all of the properties that are teleported. The Canadians scored about 25%. The forms of teleported photons were destroyed in one laboratory and recreated in another more than 8km apart in the two cities through optical fiber.
Both tests, undoubtedly, are achievements.
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And the set-ups described in studies published in Nature Photonics journal could be seen as building blocks for a future “quantum internet”. From the development of super fast quantum computers to quantum crypotography and the creation of extremely secure “quantum internet”, feasible and reliable teleportation has the capability to revolutionize communications.
