Quantum Walk Computing

[HysteryDiagnosis]

http://www.sciencedaily.com/releases/2010/09/100916145049.htm




"It is widely believed that a quantum computer will not become a reality for at least another 25 years," says Professor Jeremy O'Brien, Director of the Centre for Quantum Photonics. "However, we believe, using our new technique, a quantum computer could, in less than ten years, be performing calculations that are outside the capabilities of conventional computers."

The technique developed in Bristol uses two identical particles of light (photons) moving along a network of circuits in a silicon chip to perform an experiment known as a quantum walk. Quantum walk experiments using one photon have been done before and can even be modelled exactly by classical wave physics. However, this is the first time a quantum walk has been performed with two particles and the implications are far-reaching.

"Using a two-photon system, we can perform calculations that are exponentially more complex than before," says O'Brien. "This is very much the beginning of a new field in quantum information science and will pave the way to quantum computers that will help us understand the most complex scientific problems."

In the short term, the team expect to apply their new results immediately for developing new simulation tools in their own lab. In the longer term, a quantum computer based on a multi-photon quantum walk could be used to simulate processes which themselves are governed by quantum mechanics, such as superconductivity and photosynthesis.