The hope to see quantum computers materialize in the near future is based on a fundamentally new mode of information processing that is replacing the current theories of computation and information technology with quantum generalizations. They are a direct consequence of concepts derived from quantum mechanics among which quantum interference and the principles of superposition and entanglement are usually described as the underlying principles of the new science of quantum computing. Used together, they have the potential to solve problems far beyond the capabilities of any present-day computers.

Quantum interference is a principle that states the outcome of a given process depends on its past history and it gives quantum computing the potential of being significantly more powerful than our current computing technology. Superposition is related to the properties of waves. A string vibrates in a pattern having evenly spaces nodes, or points of zero amplitude...