Scientists from the University of Bristol’s Centre for Quantum Photonics have developed a silicon chip with circuits that can manipulate single photons of light to perform calculations. These circuits 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 that would be nonsensical in our everyday world).
The technology developed uses the same manufacturing techniques as conventional microelectronics, and could be economically scaled for mass-manufacture say the team which includes researchers from Heriot-Watt University in Scotland and Delft University in the Netherlands. These new circuits are compatible with existing optical fibre infrastructure and are ready to be deployed.
“Using silicon to manipulate light, we have made circuits over 1000 times smaller than current glass-based technologies. 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 in to technology and devices that would not previously have been compatible with glass chips," said Mark Thompson, Deputy Director of the Centre for Quantum Photonics in the University’s Schools of Physics and Electrical & Electronic Engineering. "This is very much the start of a new field of quantum-engineering, where state-of-the-art micro-chip manufacturing techniques are used to develop new quantum technologies and will eventually realise quantum computers that will help us understand the most complex scientific problems.”
Along with recent demonstrations from the Bristol research group and other groups showing on-chip generation of photonics qubits and results from the US showing on-chip detection of single photons, the research team now believes that all the key components are in place to realise a fully functioning quantum processor — a powerful type of computer that uses quantum bits (qubits) rather than the conventional bits used in today’s computers. Quantum computers will have unprecedented computational power for tasks including search engines and the design of new materials and pharmaceuticals.