Skip to comments.Japan one step closer to quantum computer
Posted on 05/05/2007 2:32:21 AM PDT by snowsislander
Scientists in Japan have made a key step toward the development of a quantum computer -- a still largely hypothetical device that would be dramatically more powerful than today's supercomputers -- according to Japanese electronics giant NEC Corp.
In what they claimed was a world first, researchers at NEC and the state-funded Institute of Physical and Chemical Research successfully demonstrated a circuit that can control the state of a pair of elemental particles and how strongly they interact with one another.
Being able to control these particles -- called "qubits" -- in this fashion may help scientists to build a quantum computer, though actually developing one still lays many years in the future, research team member Yasunobu Nakamura said Wednesday.
"These results do not change the fact that there are still many difficulties to be resolved," Nakamura said.
The NEC team, led by Jaw-Shen Tsai, published their results Thursday in the American science journal "Science."
Tsai's team has already made several major steps toward developing a quantum computer, including getting elementary particles to interact with one another and controlling their ability to seemingly be in many places at the same time, a concept known as "superposition" in quantum physics.
Quantum physics is the study of the behavior of subatomic particles, such as electrons.
Many scientists believe quantum computing -- which takes advantage of the superposition concept -- promises to solve certain factoring, simulation and other intensive problems faster than today's machines that rely on classical physics.
Earlier this year, Canadian company D-Wave Systems Inc. demonstrated a machine it claims uses quantum mechanics to solve certain types of problems. However, independent quantum physics researchers have said they are dubious of some of the company's claims as its findings have yet to be submitted for peer review -- a standard step for gaining acceptance in scientific circles.
D-Wave itself acknowledged that even it isn't entirely sure the machine -- which the company claims to be the "world's first commercial quantum computer" -- is performing true quantum calculations.
D-Wave itself acknowledged that even it isn’t entirely sure the machine — which the company claims to be the “world’s first commercial quantum computer” — is performing true quantum calculations.
This may well be the biggest problem for these researchers. The simulations that these beasts are hoped to be able to perform are so demanding that the results may not able to be verified.
If it can run Windows Vista(c) without crashing, that alone is a substantial benchmark. LOL
Yes, but at least results from some of the interesting problems are easy to verify such as integer factoring, and for which we already have Shor's algorithm ready to run once we have quantum computers with qubits available.
I followed your link, and now my brain hurts. Therefore, it is all Bush’s Fault.
Yeah, but could ya play Half Life 2 or F.E.A.R on the thing??
So who wants a computer that sheds and yanks up hair balls? I've already got two cats here at home do that.
What would be the advantages of a quantum computer over existing computers?
Some hard problems (such as factoring large composite integers that only have two large factors) would be much tractable than in any scheme known currently.
Here's an article on Quantum Computing at the Wikipedia. (Take anything you read at the Wikipedia with a big grain of salt. Hoaxes, such as the spurious 1880 Treaty of Iwo Jima, do exist on the Wikipedia.)
I’d like to factor 500 digit prime numbers in real time.
Which really means, I’d like to factor a 500 digit number into its primes, see the post above.
Thing is, it’s simultaneously crashing and not crashing.
...at least until you look at the screen.
As I understand it...
Currently, computers attack certain complex problems by iterating through all possible solutions, one at a time, which can take a very long time.
A quantum computer could instantly be in all possible solutions at once, and then persuaded to give you the best solution.
Cracking an encrypted message without having the decryption key theoretically means trying all possible keys (passwords), which can take a long time (like millenia).
A quantum computer could apply all possible keys at once, and promptly give you the one that works.
That's one thing I love about Free Republic--so many intelligent, well informed people here! ~S
It'll be an interesting version, both crashed and running fine at the same time.
There should be a warning for that on all threads dealing with quantum physics.
You beat me! I should have read the whole thread first.
Factor prime numbers??
You don’t need a computer to do that
Ok, now I get it.
According to the quantum physics theory behind these things, you can hook up a device comparable to a multiplier in a circuit, and where a normal electronic circuit will propagate forward from two factors to the product, a quantum circuit can accept an input as the product, and propagate backwards, to two factors almost immediately. Where a number has only two factors (excluding 1 and itself) this would give an almost instantaneous way to crack the large composite numbers of just 2 primes. Banks use these numbers to exchange wire transfers, and change the large composite number 3 times a second to avoid someone decrypting their transactions and inserting bogus ones, and any threat to this way of doing business is taken extremely seriously.