Research paves way for quantum enhanced computation

The researchers believe boson sampling, which takes advantage of recent developments in photonics, offers a promising route to building such a device in the not too distant future, and provides convincing evidence for the computational power of quantum mechanics. Dr James Gates, from Southampton's Optoelectronics Research Centre, explained how the technology works: "Photons are identical at a fundamental level – formally they are bosons – which means that they exhibit strong quantum level – entanglement. This means that if two sufficiently identical photons come together they behave in a connected way – almost as if they 'clump' together." When scaled up to multiple input photons, these 'entanglements' cause the outputs of a boson sampling circuit to clump together in a characteristic way, predictable by quantum mechanics, but difficult to calculate using conventional computers. Dr James worked with Professor Peter Smith, also of the University of Southampton, to develop the photonic chip on which the experiment was performed. He commented: "The chip offers a scalable route, perhaps the only scalable route, to build large linear systems required for larger boson sampling machines. "If one is going to eventually need to move on chip with more complex boson sampling machines, there is obvious benefit in building the proof of principle devices on chip as well. The move to optical processing on a chip format can be likened to the shift to integrated silicon chips in electronics." The work is part of a long term collaboration with the Clarendon Laboratory at the University of Oxford, and is being supported by the EPSRC.