title: Boson sampling on a photonic chip.
abstract: Although universal quantum computers ideally solve problems such as factoring integers exponentially more efficiently than classical machines, the formidable challenges in building such devices motivate the demonstration of simpler, problem-specific algorithms that still promise a quantum speedup. We constructed a quantum boson-sampling machine (QBSM) to sample the output distribution resulting from the nonclassical interference of photons in an integrated photonic circuit, a problem thought to be exponentially hard to solve classically. Unlike universal quantum computation, boson sampling merely requires indistinguishable photons, linear state evolution, and detectors. We benchmarked our QBSM with three and four photons and analyzed sources of sampling inaccuracy. Scaling up to larger devices could offer the first definitive quantum-enhanced computation.
authors.affiliation: Clarendon Laboratory, Department of Physics, University of Oxford, Oxford, UK. j.spring1@physics.ox.ac.uk
authors.forename: Justin B
authors.initials: JB
authors.lastname: Spring
authors.forename: Benjamin J
authors.initials: BJ
authors.lastname: Metcalf
authors.forename: Peter C
authors.initials: PC
authors.lastname: Humphreys
authors.forename: W Steven
authors.initials: WS
authors.lastname: Kolthammer
authors.forename: Xian-Min
authors.initials: XM
authors.lastname: Jin
authors.forename: Marco
authors.initials: M
authors.lastname: Barbieri
authors.forename: Animesh
authors.initials: A
authors.lastname: Datta
authors.forename: Nicholas
authors.initials: N
authors.lastname: Thomas-Peter
authors.forename: Nathan K
authors.initials: NK
authors.lastname: Langford
authors.forename: Dmytro
authors.initials: D
authors.lastname: Kundys
authors.forename: James C
authors.initials: JC
authors.lastname: Gates
authors.forename: Brian J
authors.initials: BJ
authors.lastname: Smith
authors.forename: Peter G R
authors.initials: PG
authors.lastname: Smith
authors.forename: Ian A
authors.initials: IA
authors.lastname: Walmsley