Quantum Computer

[andrew]

- Google News

New articles about the latest computer landmark today.

[Erock]

I hate to be lazy, as I could probably go read about it, but what exactly does a Quantum computer do?

Erock

[andrew]

Everything except make your coffee.

[Levent Okyay]

I read about quantum computers a long time ago. And at the time it was said we'd probably have to wait 50 years, so it's interesting that they've built some now. But the current quantum computers are still far slower than conventional computers, so proof of the theoretically power of a quantum computer, as of yet, still doesn't exist.
Anyway the company that's built one has said by the end of next year they'll have a reasonable powerful one, so we'll see what happens.

[Oliver]

The following, as I understand the idea, is the essence of quantum computing:

We can solve many problems using digital computing. Most of those can be solved exactly, the others accurately enough.

However, there exist problems which, if we attempted to solve via digital computing, would take, effectively, forever to solve.

These same problems, via quantum computing, may be solvable within an acceptable span of time.

That potential (to find the solution) comes from quantum computing's ability to simultaneously superimpose all the possible solutions and let the most likely and most accurate solutions come to the fore. Note that the best answer isn't necessarily going to be the most accurate answer. In a sense, the best answer is going to be the one that is accurate enough while being found within a short enough span of time.

The experiment referred to in the article was for a small quantum computer, if I recall correctly, using only 16 qubits. A qubit is like a bit, except that where a bit has only one value (0 or 1), a qubit can contain a value of 0, 1, or both at the same time. The next quantum computer may have 1000 qubits, vastly increasing its power.

[Doku]

Let me try to give an explination...

PROBLEM:
Picture a board with six holes in it of different shapes, with a slot connecting them all.
Picture a rod that has six blocks on it, with the blocks being odd shapes. (kinda like a shish-kabab)

If you spin the six blocks in the correct direction, the blocks and rod can pass through the board.

CURRENT CPU:
The current method of CPU working is that it has to spin the first block, and test. Spin it again, test again, etc. until it has tried every combination of the first block. Then spin the second block one position, and re-spin and re-test with the first block. Just like taking one of the bicycle chain locks, and setting them all to 0-0-0-0, then trying 0-0-0-1, 0-0-0-2, ... Eventually, you will find the answer.

QUANTUM CPU:
The Quantum method would exploit an aspect of the blocks to test all possible at the same time. For example: If you could push a block against the hole, and have it auto-align itsself... If this were the case, you could simply push the rod against the hole, and all of the blocks would rotate themselves to the proper orientation, and the rod would pass through on the first try.


Another example. Look at a crowd. Pick out three people with blonde hair. You could do that instantly, right? How about a standard CPU? Pick one person. Is their hair blond? No. Try the next, etc. The quantum computer basically creates a filter that three blonde people can pass through, then presses the crowd against it, and three pop out. It tries every combination at the same time.


How many people/blocks/... you can try at the same time is determined by how many "qbits" there are in your processor. In the case of the one that was recently created, you can try 16 at the same time.

--Curt