TORONTO – (THE CAMPING CANUCK) – Teleport. A fascinating word reminiscent of Star Trek in the 1960s, with Captain Kirk’s famous line “Beam me up, Scotty!”
Teleportation or teletransportation is the theoretical transfer of matter or energy from one point to another without traversing the physical space between them. It is a common subject in science fiction literature, film, video games, and television.
As reported in The journal “Nature Photonics” two different groups of scientists have taken quantum teleportation from the lab into the real world.
Researchers working in Calgary, Canada and Hefei, China, used existing fiber optics networks to transmit small units of information across cities via quantum entanglement — Einstein’s “spooky action at a distance.”
quantum communication network embryo, combining a user, a relay and a recipient via urban commercial optical fibers. One in China , in the vile of Hefei, the group of Jian-Wei Pan (Shanghai University) and one in Canada , in Calgary, the group of Wolfgang Kittel (University of Calgary).
Let us pause a moment on quantum entanglement, physical property on which quantum communication. It is to prepare a pair of binoculars, usually particles of photon-mix so intimately, their properties any change to the status of a de facto change the other. Instant change, regardless of the distance between them! This principle of entanglement is used to convey key for encoding and decoding secret messages safe from eavesdroppers: the laws of quantum physics guarantee that an intrusion will be immediately identified.
Quantum cryptography devices connecting two points are marketed for ten years, including the Swiss firm ID Quantique , born of the work of Nicolas Gisin at the University of Geneva. “Commercial systems run up to 100 km, while in the lab, commonly 300 km is reached,” explains Gregoire Ribordy, the president of the company. To go further, you must install signal repeaters. “Today, in the first quantum relays information happens is converted into a classic -détectable information espion- before being re-emitted in quantum form.” The Chinese government has secured the first relay quantum coupling of magnitude in the world, between Shanghai and Beijing (2000 km), which will open in mid-November. “To have a 100% quantum relays, it must appeal to the teleportation” says Nicolas Gisin.
Imagine a person, Alice, wants to send information to a person we’ll call Bob. First names chosen by cryptography experts to facilitate their discussions. First, prepare a pair of entangled photons, one of which will be held by Alice, and the other by Bob. Then, Alice made her entangled photon interact with a third -He which carries the information to be transmitted. The state of Alice’s entangled photon is altered, resulting in -instantanée- change his alter ego at Bob. When the third photon, it was destroyed -absorbé- during the operation.
This principle is used in the Canadian experience (about 6.2 km) and China (about 14.7 km) recounted today, ten years after the similar work of Nicolas Gisin group at shorter distance. It is this time of exchanging information between Alice and Bob, via a relay named Charlie. In both experiments, Alice sends quantum information to Charlie, who is responsible for teleport to Bob; the link remains quantum end to end. But both have the same limitation: “We lack a true optical memory to progress,” concedes Zhang Qiang, co-author of the Chinese study. “When the information arrives Alice, you have to make wait while Charlie and Bob have a pair of entangled photons, explains Nicolas Gisin. As we did in 2007, my colleagues the delay in a long fiber wound on itself. But the storage time is dictated by the length of the fiber. In an optical memory, it releases the information on demand. ”
Such memories already exist. “Our component can store information for a millisecond, says Nicolas Gisin. We want to reach the second “The surprise could come from China.” It is clear that Beijing will not entrust the transport of its secrets to a foreign technology; the government uses it, “says the physicist. While Europe spends one billion euros in ten years to all quantum technologies, Beijing spends the same amount over five years and only on quantum communications! Effective bet “Over ten companies like ours, four are Chinese,” worries Grégoire Ribordy.
Even before the quantum highway Beijing-Shanghai is completed, many small networks have already been connected. The beginnings of an Internet backbone ultra-secure yet unique. And that’s not all: last year in August, Beijing launched a “quantum satellite.” “We obviously do not know the details, says Nicolas Gisin, but obviously he carries everything you need to try experiments point to point cryptography and teleportation.”