Posted on 06/17/2004 11:59:00 AM PDT by ckilmer
Teleportation breaks new ground 16 June 2004
Physicists in Austria and the US have independently demonstrated quantum teleportation with atoms for the first time. Until now, teleportation had only ever been observed with photons. The results could represent a major step towards building a large-scale quantum computer.
In quantum teleportation, the sender, normally called Alice, instantaneously transfers information about the quantum state of a particle to a receiver called Bob. The uncertainty principle means that Alice cannot know the exact state of her particle. However, another feature of quantum mechanics called "entanglement" means that she can teleport the state to Bob.
Entanglement allows particles to have a much closer relationship than is possible in classical physics. If two particles are entangled, we can know the state of one particle by measuring the state of the other. For example, two particles can be entangled such that the spin of one particle is always "up" when the spin of the other is "down", and vice versa. An additional feature of quantum mechanics is that the particle can exist in a superposition of both these states at the same time.
Quantum teleportation
David Wineland and colleagues from the National Institute of Standards and Technology (NIST) in Colorado began by creating a superposition of spin up and spin down states in a single trapped beryllium ion (Nature 429 737). Using laser beams, they teleported these quantum states to a second ion with the help of a third, auxiliary ion (see figure). The NIST technique relied on being able to move the ions within the trap.
Meanwhile, Rainer Blatt and co-workers at the University of Innsbruck performed a similar experiment using trapped calcium ions (Nature 429 734). However, rather than moving the ions, they "hide" them in a different internal state.
The success of a teleportation experiment is judged by its fidelity value -- a figure of merit that shows how faithfully the quantum state of the first system has been reproduced in the second system. Both the Innsbruck and NIST groups achieved fidelity values of around 75%. By comparison, approaches that do not use entanglement cannot achieve fidelity values above 66.6%.
"Teleporting the quantum state of an atom is important and exciting for scaling up quantum computers," Blatt told PhysicsWeb. "It can be applied to distributed quantum information processing, and together with interfacing techniques -- which are still under investigation -- for networking between different nodes in a quantum computer."
Author Belle Dumé is Science Writer at PhysicsWeb
This is remarkable. Of course, Star Trek teleportation is still far off. A 75% quantum-state fidelity on ONE atom would not scale up to be nearly as good as the result they got in "the Fly".
Beam me up Scottie!
ping
What might the implications be on communication devices because of this? Does this mean there could be instantaneous communication over an infinite amount of space? If so, wow! That might really open up some amazing possibilities.
Heelp Me ... Heelp Me
Is that from the original? Whatever happened to the cat?
I'd have a better shot at diagraming Hillary's Vast Rightwing Conspiracy than understanding Quantum Physics.
I LOVE science fiction!! Sooner or later, it becomes science fact. At the rate that this is proceeding, "Star Trek"-type teleportation will be routine by the end of this century.
What a neat invention science will be bringing to our future!!
bump
In quantum teleportation, the sender, normally called Alice, instantaneously transfers information about the quantum state of a particle to a receiver called Bob. The uncertainty principle means that Alice cannot know the exact state of her particle. However, another feature of quantum mechanics called "entanglement" means that she can teleport the state to Bob.
What bunk! Me and Alice teleport all over the place anytime we feel like it. When I go to Saturn and Jupiter, I don't take Amtrak.
Question, is the instantaneous transfer of information teleportation? How "instantaneous" is this, I.E. faster than light?
I thought nothing with mass can exceed the speed of light, does information necessarily have mass?
So it's as I thought, if you wanted something with mass to "travel" from point A to B you would still have to recreate the mass at the other end from the information provided, like sending a fax.
So it's as I thought, if you wanted something with mass to "travel" from point A to B you would still have to recreate the mass at the other end from the information provided, like sending a fax.
Read Crichtons book "Timeline". Fiction-yes but based on current scientific lab results with many reference leads.
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