# Does anyone know about Quantum Computing?

1. Feb 24, 2009

### budder8819

Just wondering if anyone on this forum has an extensive knowledge that they would like to share. I've heard that the basic concept in quantum computing has something to do with representing binary information with a variable 1 or 0. Something like that. I was trying to follow but it was very hard. I'm undergraduate electrical engineer and am trying to explore some fields I'd like to go into.
Thanks for sharing

2. Feb 25, 2009

### QuantumBend

Yes, quantum computers have 0, 1 AND 01. Not two they have three. Needs Turing 3 state and 4 color MACHINE then do all things. NOT quantum computer in shop only labaratary.

3. Feb 25, 2009

### Naty1

not extensive...barely superficial....

Well if you want to get in on the ground floor of a new technology this is one to consider as its in its infancy.....huge obstacles to overcome...

check http://en.wikipedia.org/wiki/Quantum_computing

Quantum computers are theoretically more power than classical computers...quantum information theorists talk in terms of qubits, quantum bits. Question might be resolved in N^1/2 instead of N questions....potentially big advances in spped/power...

Try reading Charles Seife, DECODING THE UNIVERSE, Chapter 7, Quantum Information for the theory basics. One area that has shown theoretical promise is factoring numbers...the basis for cryptography...
As far I know not much practical has been accomplished yet, but the knowledge about the quantum world has been substantial.

4. Feb 25, 2009

### Tac-Tics

An idealized classical computer deals with arrays of bits. A single bit is an object with two states. An array of states just means we're working with an ordered list of bits. If you have n bits of storage, then your system can be in any of 2^n states.

In a quantum computer, things are a bit different. Individual qubits don't have a definite value, only an amplitude for eahc possible value. Even more intriguing is that qubits can be entangled. This means that we don't just assign each qubit its own amplitude, but we assign an amplitude to each possible state of the entire array. Measuring the array collapses the quantum state to a classical state.

On the surface, it seems like it might not benefit you. With an n-qubit array, you can store 2^n states, but as soon as you measure it, your state is lost. But there are little tricks you can use to speed things up. Functions which act on quantum registers are essentially able to apply the function to every possible argument simultaneously. For certain problems, if you set up the right entangled state, run the right function, and then "undo" the entangling, you can obtain the answer in fewer steps than any classical algorithm.

The simplest such algorithm is called the Deutsch-Jozsa algorithm.