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February 6, 2009, 11:22 AM
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  • Teleportation

  • But what if there were a way to get you from your home to the supermarket without having to use your car or from your backyard to the International Space Station without having to board a spacecraft? There are scientists working right now on such a method of travel, combining properties of telecommunications and transportation to achieve a system called teleportation. In this article, you will learn about experiments that have actually achieved teleportation with photonsand how we might be able to use teleportation to travel anywhere, at anytime.

    What is Teleportation?

    Teleportation involves de-materializing an object at one point, and sending the details of that object's precise atomic configuration to another location, where it will be reconstructed. What this means is that time and space could be eliminated from travel we could be transported to any location instantly, without actually crossing a physical distance.

    Most of us were introduced to the idea of teleportation, and other futuristic technologies, by the short-lived Star Trek television series (1966-69) based on tales written by Gene Roddenberry. Viewers watched in amazement as Captain Kirk, Spock, Dr. McCoy and others beamed down to the planets they encountered on their journeys through the universe.

    In 1993, the idea of teleportation moved out of the realm of science fiction and into the world of theoretical possibility. It was then that physicist Charles Bennett and a team of researchers at IBM confirmed that quantum teleportation was possible, but only if the original object being teleported was destroyed. This revelation, first announced by Bennett at an annual meeting of the American Physical Society in March 1993, was followed by a report on his findings in March 29, 1993 issue of Physical Review Letters Since that time, experiments using photons have proven that quantum teleportation is in fact possible.

    Photon Experiments

    In 1998, physicists at the California Institute of Technology (Caltech), along with two European groups, turned the IBM ideas into reality by successfully teleporting a photon, a particle of energy that carries light. The Caltech group was able to read the atomic structure of photon, send this information across 1 meter (3.28 feet) of coaxial cable and create a replica of the photon. As predicted, the original photon no longer existed once the replica was made. In performing the experiment, the Caltech group was able to get around the Heisenberg Uncertainty Principle, the main barrier for teleportation of objects larger than a photon. This principle states that you cannot simultaneously know the location and the speed of a particle. But if you can't know the position of a particle, then how can you teleport it? In order to teleport a photon without violating the Heisenberg Principle, the Caltech physicists used a phenomenon known as entanglement . In entanglement, at least three photons are needed to achieve quantum teleportation:

    Photon A: The photon to be teleported
    Photon B: The transporting photon
    Photon C: The photon that is entangled with photon B
    If researchers tried to look too closely at photon A without entanglement, they would bump it, and thereby change it. By entangling photons B and C, researchers can extract some information about photon A, and the remaining information would be passed on to B by way of entanglement, and then on to photon C. When researchers apply the information from photon A to photon C, they can create an exact replica of photon A. However, photon A no longer exists as it did before the information was sent to photon C.

    In other words, when Captain Kirk beams down to an alien planet, an analysis of his atomic structure is passed through the transporter room to his desired location, where a replica of Kirk is created and the original is destroyed.

    A more recent teleportation success was achieved at the AustralianNationalUniversity , when researchers successfully teleported a laser beam While the idea of creating replicas of objects and destroying the originals doesn't sound too inviting for humans, quantum teleportation does hold promise for quantum computing. These experiments with photons are important in developing networks that can distribute quantum information. Professor Samuel Braunstein , of the University of Wales , Bangor , called such a network a "quantum Internet." This technology may be used one day to build a quantum computer that has data transmission rates many times faster than today's most powerful computers.

    Quantum Teleportation

    Teleportation is the name given by science fiction writers to the feat of making an object or person disintegrate in one place while a perfect replica appears somewhere else. How this is accomplished is usually not explained in detail, but the general idea seems to be that the original object is scanned in such a way as to extract all the information from it, then this information is transmitted to the receiving location and used to construct the replica, not necessarily from the actual material of the original, but perhaps from atoms of the same kinds, arranged in exactly the same pattern as the original. A teleportation machine would be like a fax machine, except that it would work on 3-dimensional objects as well as documents, it would produce an exact copy rather than an approximate facsimile, and it would destroy the original in the process of scanning it. A few science fiction writers consider teleporters that preserve the original, and the plot gets complicated when the original and teleported versions of the same person meet, but the more common kind of teleporter destroys the original, functioning as a super transportation device, not as a perfect replicator of souls and bodies.

    In 1993 an international group of six scientists, including IBM Fellow Charles H. Bennett, confirmed the intuitions of the majority of science fiction writers by showing that perfect teleportation is indeed possible in principle, but only if the original is destroyed. In subsequent years, other scientists have demonstrated teleportation experimentally in a variety of systems, including single photons, coherent light fields, nuclear spins, and trapped ions. Teleportation promises to be quite useful as information processing primitive, facilitating long-range quantum communication (perhaps ultimately leading to a "quantum internet"), and making it much easier to build a working quantum computer. But science fiction fans will be disappointed to learn that no one expects to be able to teleport people or other macroscopic objects in the foreseeable future, for a variety of engineering reasons, even though it would not violate any fundamental law to do so.

    In the past, scientists did not take the idea of teleportation very seriously, because it was thought to violate the uncertainty principle of quantum mechanics, which forbids any measuring or scanning process from extracting all the information in an atom or other object. According to the uncertainty principle, the more accurately an object is scanned, the more it is disturbed by the scanning process, until one reaches a point where the object's original state has been completely disrupted, still without having extracted enough information to make a perfect replica. This sounds like a solid argument against teleportation: if one cannot extract enough information from an object to make a perfect copy, it would seem that a perfect copy couldn't be made. But the six scientists found a way to make an end run around this logic, using a celebrated and paradoxical feature of quantum mechanics known as the Einstein- Podolsky -Rosen effect. In brief, they found a way to scan out part of the information from an object A, which one wishes to teleport, while causing the remaining, unscanned , part of the information to pass, via the Einstein- Podolsky -Rosen effect, into another object C which has never been in contact with A. Later, by applying to C a treatment depending on the scanned-out information, it is possible to maneuver C into exactly the same state as A was in before it was scanned. A itself is no longer in that state, having been thoroughly disrupted by the scanning, so what has been achieved is teleportation, not replication.

    Spy Networks And Financial organizations are the beneficiaries:

    Spy networks and international financial systems are set to benefit from a significant advance in teleportation technology developed at The Australian National University. ANU researchers in Canberra have announced that they are the first in the world to demonstrate the sharing of secrets via teleportation using quantum physics. The research has potential to significantly enhance the security of computer systems around the world.

    The researchers provided a window on the future of telecommunications by demonstrating the production, disembodiment and successful reconstruction -- or teleportation -- of a message to a network of participants. The experiment was conducted by 24-year-old PhD student Andrew Lance and Dr Thomas Symul from the Quantum Optics Group in the ANU Faculty of Science, in collaboration with Professor Barry Sanders from the University of Calgary in Canada .

    The research, published in the latest edition of Physical Review Letters, is expected to attract attention from defence and finance industries around the world. It builds on the teleportation work conducted by Dr Warwick Bowen and Dr Ping Koy Lam at the ANU in 2002, when they teleported information using a laser beam. "This is a much more complex form of information teleportation in the sense that it involves multiple recipients," Dr Lam said. Acting ANU Vice-Chancellor Professor Lawrence Cram congratulated the team on their success.

    The researchers used crystals, lenses and mirrors to produce a pair of 'entangled' laser beams that are then used to carry fragile information in the form of quantum states. These quantum states cannot be measured or copied, making eavesdropping impossible. The transmission of the light beams constitutes a secret communication scheme with guaranteed security.

    The process of secret sharing is a fundamental part of present day telecommunication, computer and banking practices. Such network communication can be enhanced using the laws of quantum physics to protect the information -- a process called quantum state sharing. "The benefit of this technology is that the encrypted message can only be decoded by a majority of recipients. For example, if an encrypted message was sent to a spy network containing 15 individuals, a minimum of eight agents would be needed to access the message -- limiting the chances of the message being infiltrated or deleted by a double-agent," Mr. Lance said. "The system could also have major applications as a fail-safe mechanism in operating systems for the new generation of super-fast quantum computers." Barry Sanders, iCORE Professor and Director of the newly launched Institute for Quantum Information Science at the University of Calgary , said; "Security is crucial for quantum networks that may someday deliver ultra fast solutions to certain computational problems and for communication that is impervious to eavesdroppers. Our experiment demonstrates that quantum networks can be protected from component failures and malice."

    Then visualize or feel the object leaving your hands in a word d

    How To Sound Like An Expert

    Everybody knows about teleportation. But many people's knowledge is derived entirely from sci-fi books and movies, not from any real science. You can often spot these individuals by their tendency to refer to teleportation as something primarily done by humans (or aliens), and done by them of their own volition, in the same way you might decide to, say, stand up, or make a phone call. Physicists use a somewhat different vocabulary when discussing teleportation (even though many of them are active sci-fi fans when they're away from the lab, so can speak both languages).

    Where does the word "teleportation" come from?

    Zero points if your answer is The Twilight Zone. The strictly accurate answer for people with large foreheads is that it derives from two words: " telos " - from the Greek, meaning "end" or "endpoint", and " portare " from the Latin, meaning "to carry". So teleportation means, "to carry to an endpoint"... So, there are many interpretations, but the essential characteristic of teleportation though is that it is instantaneous and has no regard for distance between origin and destination.


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