New breakthrough brings quantum computer closer to reality

Researchers have made an important advancement towards a quantum computer by shrinking down key components and integrating them onto a silicon microchip.

Scientists and engineers from an international collaboration led by Dr Mark Thompson from the University of Bristol have, for the first time, generated and manipulated single particles of light (photons) on a silicon chip - a major step forward in the race to build a quantum computer.

The latest advancement is one of the important pieces in the jigsaw needed in order to realize a quantum computer. While previous attempts have required external light sources to generate the photons, this new chip integrates components that can generate photons inside the chip.

Lead author Joshua Silverstone said that they were surprised by how well the integrated sources performed together, asserting that they produced high-quality identical photons in a reproducible way, confirming that we could one day manufacture a silicon chip with hundreds of similar sources on it, all working together. This could eventually lead to an optical quantum computer capable of perform enormously complex calculations.

Group leader Thompson said that single-photon detectors, sources and circuits have all been developed separately in silicon but putting them all together and integrating them on a chip is a huge challenge, asserting that their device is the most functionally complex photonic quantum circuit to date, and was fabricated by Toshiba using exactly the same manufacturing techniques used to make conventional electronic devices.

The findings have been published in the journal Nature Photonics.