Quantum Dots Might Be Key For Teleportation

prostoalex writes "Researchers from Nanyang Technological University in Singapore have created a model teleportation system using quantum dots. PhysOrg reports that 'tiny clusters of atoms known as quantum dots may be excellent media for quantum teleportation, a physics phenomenon in which information — in the form of a quantum state, a very specific mathematical signature of an atom — can be transmitted almost instantaneously to a distant location without having to physically travel through space.'"

Comments

NOT a matter transporter

[Cousarr]

Quantum entanglement is a great way to get information from one location to another at faster than the speed of light but offers no way to transmit matter. Theoretically the precesses here allow for technology like the ansible from Card's Ender's Game series but won't be transmitting ensign Ricky to his death from aboard the starship enterprise. Now, if we were all information-based entities teleporting about using quantum entanglement would be highly feasible.

Re:NOT a matter transporter

[Anonymous Coward]

Your post is almost rigth. Quantum entanglement is used for quantum teleportation but in no way can informaion be transmitted faster than light. In fact in order to be able to teleport somehing, some classical information has also to be exchanged.

Re:NOT a matter transporter

[asuffield]

I've also always wondered what would keep someone from just creating many copies of themselves. A transporter would never truly transport you. It would simply map your makeup here and assemble the same thing somewhere else. But that isn't to say that you'd have to destroy the version at point A from which the map came.

Various fundamental results have already been formally proved about quantum physics. One of them is the no cloning theorem, and one of its many implications is that no duplication is ever possible: copying anything on a quantum level must always involve destroying the original.

Another proven result is the no teleportation theorem. This one indicates that quantum matter teleporters are fundamentally impossible. It just can't be done. It's not a problem with scale or accuracy, you cannot even teleport a single atom.

These two theorems are not based on vague arguments, but on the mathematics underlying quantum physics. As such they are iron-clad.

If either a working duplicator or teleporter is ever built, we already know that it will not be based on quantum physics, but on some lower level of physics that has not yet been discovered. This is unlikely to happen in our lifetimes (it takes roughly 100-200 years to move from one level of physics to the next, based on history).

Re:NOT a matter transporter

[SEWilco]

The risk of cancer from DNA corruption scares the hell outta me.

Alteration of DNA is not as disastrous to the body as you might think. The decay of a C-14 atom in DNA happens about 50 times per second, changing a carbon atom to one of nitrogen. So there is DNA corruption in about 50 of your cells each second from that cause alone. How often that has disastrous consequences for each cell is somewhat relevant to the body.

Read the discussion...

[niceone]

The article is pretty light on information, but hte discussion has a pretty thorough description of why this can't (AFAIK) be used to send information, including a link to the wikipedia topic. Maybe they have a way round that, but you can't tell from the article.

Re:Cool.

[Derosian]

A good place to start 'understand' quantum mechanics is to see the double slit experiment. Link.

Re:A little confused...

[asuffield]

I was under the impression that quantum entanglement could not transmit information. If these researchers have actually managed superluminal commmunication, then... wow.

It cannot transmit information faster than the speed of light. It can transmit information when combined with a classical, slower-than-light transfer. It cannot transmit any information without having a classical (non-quantum) information transfer also take place, so the speed is limited by the speed of the classical transfer.

As you would expect, the utility of this is somewhat limited.

Faulty assumption

[cat_jesus]

Assuming that you can determine when the quantum waveform collapses

This is the faulty assumption.

Think of of entanglement this way. You have two roulette wheels and they are "entangled". What this means to the roulette wheels is that they are spinning and the marbles are bouncing along inside them synchronously(I know they'd be at right angles but being the same value works well for the visualization). So you split them up and one roulette wheel is in another galaxy and the other is here. Both are spinning and the marbles are still bouncing around in sync. If you stop one, the other keeps going. If you stop them at the same time the marbles will have the same value. But the problem is the one you assume away. You cannot tell that the other roulette wheel has stopped.

In QE, if you attempt to observe the entanglement, you make it collapse. You can't tell what the state of the particle is without destroying the entanglement.

IINAQP and I could be wrong. But this is my understanding and my cousin who is a Physicist tells me I have an accurate, if rudimentary, understanding of this particular phenomenon.

I wish you were right.

Re:Cool.

[Davey McDave]

That's basically quantum computing for you. You can get them involved in such a state that they can influence one another even though they're not even next to one another (action at a distance). Hence they're sort of invisibly entangled within one another, if you mess around with one the other will instantly change. This is pretty great though, because if you can get all these things to represent a calculation, and act upon it, it instantly changes at this other place you can read them. Even better, if someone else tries to read it at the other place it'll show up back at the origin.

Quantum isn't really a buzzword, it actually means that it's taking advantage of the fact that energy is discrete rather than continuous. It's supposed to be used in opposition to classical or Newtonian mechanics, which assumes that energy is continuous, and has a huge amount of crazy consequences.

If you're REALLY interested in learning about quantum mechanics I'll one up the sister post and recommend you some of Feynman's lectures. In the first video here he whips through almost the entire history of physics and why QM is different: http://www.vega.org.uk/video/subseries/8