BRISTOL, UK – A new silicon-based approach to quantum computing could make the technology easier to mass-produce. Scientists at the University of Bristol’s Centre for Quantum Photonics, leading an international collaboration, made the leap from glass-based circuits to silicon by developing quantum chips from the workhorse semiconductor material used to build electrical processors in all computers and smartphones. An example of the silicon quantum chip next to a 20-pence coin. “Using silicon to manipulate light, we have made circuits over 1000 times smaller than current glass-based technologies,” said Mark Thompson, deputy director of the Centre for Quantum Photonics. “It will be possible to mass-produce this kind of chip using standard microelectronic techniques, and the much smaller size means it can be incorporated into technology and devices that would not previously have been compatible with glass chips.” Unlike conventional silicon chips that work by controlling electrical current, however, these circuits manipulate single particles of light to perform calculations. They exploit strange quantum mechanical effects such as superposition (the ability for a particle to be in two places at once) and entanglement (strong correlations between particles separated by even vast distances). Doctoral student Erman Engin measures the performance of a silicon quantum chip developed at the University of Bristol’s Centre for Quantum Photonics to replace glass-based circuits. “This is very much the start of a new field of quantum engineering, where state-of-the-art microchip manufacturing techniques are used to develop new quantum technologies and will eventually realize quantum computers that will help us understand the most complex scientific problems,” Thompson said. The team announced its results at the 2012 British Science Festival in September.