Chip could speed development of quantum computers

Quantum computers could become a reality 20 years earlier than expected following the development of an optical chip by Bristol University.

Researchers from the university’s Centre for Quantum Photonics claim they have uncovered a new route to building a quantum computer that can perform calculations currently impossible using today’s systems.

‘At the moment, people have a conventional way to realising a quantum computer and it’s widely accepted that it is likely to be at least another 25 years before we have such a device,’ said project leader Jeremy O’Brien. ‘We’ve developed a quantum walk process that we’re optimistic could lead to a quantum system in the next five years.’

A quantum walk is the path a single photon of light takes as it travels through a network. The basic principle has been demonstrated in the past using experiments in classical wave physics. O’Brien’s technique, however, is the first to use two identical photons simultaneously.

‘With a two-photon system, we can perform calculations that are exponentially more complex than before,’ he added. ‘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.’

Ultimately O’Brien hopes that a quantum computer based on a multi-photon quantum walk could be used to simulate natural processes, which themselves are governed by quantum mechanics.

‘We could use such a system to simulate processes such as photosynthesis that relies on a coherent phenomena for its operation,’ he said. ‘If we understand how photosynthesis works using a quantum walk, then we might be able to design even better mechanisms for harvesting light for energy.’