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Tiny Holes Advance Quantum Computing
Nick writes "Worldwide, scientists are racing to develop computers that exploit the quantum mechanical properties of atoms - quantum computers. One strategy for making them involves packaging individual atoms on a chip so that laser beams can read quantum data. Scientists at Ohio State University have taken a step toward the development of quantum computers by making tiny holes that contain nothing at all. The holes - dark spots in an egg carton-shaped surface of laser light - could one day cradle atoms for quantum computing."
Not necessarily. We still have a long way to go before we have useful quantum computers, and they're not an improvement over silicon for everything. We may well have diamond computers or something else fundamentally similar to silicon computers before we make the leap to quantum.
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That's supposed to be, once we understand the basics.. From what I remember of a lecture, the real issue is actually being able to control the particle itself, but once controllable, the powers are immense.. for example, it would be possible to tell if an email has been read by "simply" observing the state of the quantum particles. Extremely advanced stuff but hugely powerful for the distant future,.
I have a hole, I place a golf ball in it - I still have a hole. It just happens to have a golf ball. The difference is one is an empty hole, the other is not.
I mod down so you can mod up. Your welcome.
Going back to the same metaphor you began to use, the principle that the Schroedinger's Cat Experiment is suppposed to illustrate is not the concept of superposition (that the cat is both alive and dead whilst in its quantum state in the box) but the concept of decoherence of the quantum state under observation.
It's currently a postulate of quantum mechanics (i.e. everyone observes this phenomenon but nobody can explain it) that observation of a quantum state in a superposition (say, a "qubit" -- perhaps an electron spinning up for 0 and down for 1) will have one of the two values, with certain probability. Once read, the state loses that superposition and remains in the observed state (Recall: in the SCE, the cat stays alive or dead once you open the box).
If you don't want to measure your qubits, and thus maintain their superpositions, entanglements, etc., that's fine ... of course, you can't get any information out of them. If you've properly designed your quantum machine, you may have a guess as to what the possible states are; you may even know the probability of each one.
As soon as you ask to see a qubit, however, it becomes a classical bit and stays one. That's the downside to all this quantum stuff.
Quantum computers also do not mean an end to binary -- currently, since humans have, and are trained to use, primarily classical faculties, quantum research is aimed at extending classical computation. So we typically discuss a "qubit" which may be 0, 1, or some combination thereof (specifically residing in the field C x C). But, if we ever want to interface a quantum computer with a classical instrument (for example, some sort of I/O device, or a classical computer, or a human) then we will unavoidably devolve back to binary.
For more information, I recommend Nielsen & Chuang's book on Quantum Computation and Quantum Information (I think; I don't have it in front of me right now).
Disclaimer: I am not a quantum mechanic. I am, however, an junior finishing up my degrees in mathematics and computer science so that I can go on in a year to work on a PhD in quantum computation. --0x4a6d74
A better explaination would be, "Is it a one or a zero?" "Depends on your perspective."
Quantum computing, as I understand it (IANAQCS/P) works off the principal of super position; the ability for a bit to represent multiple bits, simply by the spin of the electron, or some other random thing that I wouldn't know how to explain.
If you defined a zero as a square, and a one as a circle, then a quantum bit would be a cylinder; from one perspective you see the square, yet turn it on its side and you see its other property. But since you have other posibilities (cubes and spheres in this system), the "third dimension" persay has to be explicitly asked for by the requesting computer.
So it's able to perform a massive amount of calculations based on a little bit of data, and store it as one neat little package at the end (either the cube, the sphere, or the cylinder). When someone comes along to ask, "was the answer a zero or a one" then, the only way to answer is "depends on the perspective".
"Victory means exit strategy, and it's important for the President to explain to us what the exit strategy is." G.W.Bush
Whoa. A Slashdotter who actually knows who Paul Harvey is? What's this world coming to? ;-)
Javascript + Nintendo DSi = DSiCade
"How about our Scientists rescue the Hubble Telescope first, something we know works, then worry about the quantum chip later."
No, but first, our scientists have to clean their teeth, then our scientists will be asleep for the next eight hours. Once our scientists have got up in the morning, they'll have a bowl of cheerios and then read the paper for a bit. Then maybe they can tackle the Hubble telescope problem (although the fact that all n million of them are trying to write on the blackboard at the same time does mean they won't make much progress. And the biologists have to sit around twiddling their thumbs because there's not much they can do to help). After Hubble, there's some promising work on cancer they need to finish up, before they can get on with a bit of geology.
Hopefully, someday soon, our scientists will realise that they can get much more done if they allow small groups of themselves to concentrate on different things, so they can make progress in different fields at the same time. In the mean time, though, you're right. They're all wasting their time on this pointless quantum computing nonsense.
Someone did answer. The mods were unkind to him, however. I hope they get their butts kicked in metamod. :-(
"Learning is not compulsory... neither is survival."
--Dr.W.Edwards Deming
Something to bear in mind is that when we talk about particle spin, "spin" is a metaphor. There isn't an actual rotation of a material object involved.
"spin" is just a label we've adopted for an abstract property of particles for which we don't have a good name otherwise. It becomes more obvious in e.g. quantum chromodynamics, where we use labels like "color" to describe particles.
Sadly, it's all too easy to mistake the map for the territory here.
In physics, even the notion of particles is a metaphor for stuff happening in specific places (at least when we're looking) and existing in discrete quantities, but taking the metaphor too far (e.g. reasoning as if they were actually tiny little solid spheres) eventually leads to conclusions that don't match what happens in the physical world.
And, that's what actually matters in the end. Not my assertions or those of the GP, but what experiments demonstrate about how the physical world behaves. The metaphors are just descriptive.
DNA just wants to be free...