- 08 Aug '14 07:55 / 8 editsIs there anyone here on this forum that is a real expert on quantum computers or at least studied their limitations?

if so, I have a question that I wanted answered for a very long time but first:

I understand that quantum computers would be suitable only for doing a very limited range of kinds of calculation. For example, if you wanted to multiply two numbers together, even two very large numbers, you would be better off using a pocket calculator or a classical computer as a quantum computer wouldn't offer any special speed advantage doing that.

One thing all the tasks that are suitable for quantum computers to do have in common is that they all involve considering a vast number of possibilities because quantum computers can be made to in effect simultaneously deal with a vast number of possibilities which is what gives them their speed advantage. But it is my understanding that even many if not most problems involving considering a vast number of possibilities are not suitable for quantum computers to deal with because there are all sorts of subtle constraints and limitations on what quantum computers can do.

Bearing that in mind, this is my question:

Is it possible for a quantum computer to analyze all the possible ways you can arrange (by chemically bond to each other ) , say, 100 atoms of common chemical elements (such as carbon, silicon, hydrogen etc ) , to work out which stable molecule that can be made with 100 atoms would absorb light and result in the greatest energy efficiency conversion of solar energy into electrical energy for use in a solar cell?

Obviously, the number of possible ways you can arrange 100 such atoms to form a stable molecule must be vast; something like 10 to the power of one million or something ridiculous like that but still not infinite. It would take an eternity for a classical computer to work out the answer to this so I think it would be very nice if a quantum computer could just give us the answer to this by exploring all the vast number of possibilities in one go and compere them all!

-possible or pure fantasy? - 08 Aug '14 08:39
q

From what I read, the ability of a quantum computer to do those kind of operations depends on the number of elements or qubits in a computer.*Originally posted by humy***Is there anyone here on this forum that is a real expert on quantum computers or at least studied their limitations?**

if so, I have a question that I wanted answered for a very long time but first:

I understand that quantum computers would be suitable only for doing a very limited range of kinds of calculation. For example, if you wanted to multiply two nu ...[text shortened]... all the vast number of possibilities in one go and compere them all!

-possible or pure fantasy?

They need more qubits than a standard computer uses in its word length, say now we have 64 bit computers and some 128 bit ones and so forth, quantum computers I think need a couple thousand qubits all working together to get a vast job done like you talk about.

That about covers MY vast knowledge of quantum computers though