Quantum Computer: Enlighten me,...us?

I am told that a quantum computer is the ultimate computer.

Can somebody explain to me in comprehendable language how it does work and what the power is compared to the high-end computer-systems of today? Maybe somebody can also tell me how far gone we are before we can use such a QC in a home situation.

Thx.

reply to post by zatara


I was going to write out a long, personal explanation but found the following link will explain it probably better than I ever could:

Quantum Computing

reply to post by zatara


I understand that it actually doesn't work because there is always the factor of observer that prevents electrons from spinning in both directions at the same time.

Originally posted by archasama
reply to post by zatara

 

I understand that it actually doesn't work because there is always the factor of observer that prevents electrons from spinning in both directions at the same time.

Yep, more or less;

However, when a measurement of any type is made to a quantum system, decoherence breaks down and the wave function collapses into a single state. Therefore, the computer has to somehow continue making these calculations without having any measurements made until the proper time, when it can then drop out of the quantum state, have a measurement taken to read its result, which then gets passed on to the rest of the system.

Link: physics.about.com...

Some of you may have seen not to long ago, but they have actually made half a prototype, and it works, they are working on the other half. Shouldn't be to long until it is finished.

They do work. MIT has one. There was a BBC show on 'What is Reality?' A few weeks back, they got a guy on from MIT with the uber-computer :p

To solve the problem with observing is that basically the quantum bits fly around in circles in a super-cooled vacuum which is so close to absolute zero that it makes it hard for larger bits to bump into it (observe it).

In power terms basically it can do both 0 1 and 01 at the same time.... The MIT guy said something along the lines of "If the quantum computer was the size of this room, it'd be more powerful than a normal computer the size of the universe". Who knows if he was being terribly accurate

reply to post by Death_Kron


Thanks for the invitation but Wikipedia is a little to technical for me.....I am not interested and would not understand the tech-language anyways. I understand that a computer works with 0's and 1's and that a decision is made with that information. But how can the status of being a zero and an one the same moment be significant for a better computer? The properties of material used and the problem to keep them from being observed are of no interest to me. All I would like to know is a simplefied explanation of the mechanics which make them so incredible and some of its mind-boggling applications.

I read that tempretures close to absolute zero are needed to make it work and is one of the problems to down-size it. What else is there to say about these computers?

reply to post by zatara


Well I'm not trying to be funny but if your that interested in how something works would you not be prepared to put a little research into it of your own?

Anyway, to answer your question in short, traditional computing uses either an ON or OFF signal (1 or 0) at the most basic level i.e. binary

Quantum computers have four states as opposed to two, hence the faster speed...

Quantum computers have four states as opposed to two, hence the faster speed...

A quantum bit is a superposition of 0 and 1. But it is still a bit.

As far as I understand it. A quantum computer is operating on a number of quantum bits or actually the superposition of them. The interesting thing about superposition is, that you are able to represent a byte using 3 quantum bits. The internal state(complexity of the quantum computer) grows exponentially 2^N. Thus they can be much faster than current computers.

The problem/challenge is to describe the computation/algorithms as quantum operations on the qubits. There is no real hardware(logic gates).