title: Photonic boson sampling in a tunable circuit.
abstract: Quantum computers are unnecessary for exponentially efficient computation or simulation if the Extended Church-Turing thesis is correct. The thesis would be strongly contradicted by physical devices that efficiently perform tasks believed to be intractable for classical computers. Such a task is boson sampling: sampling the output distributions of n bosons scattered by some passive, linear unitary process. We tested the central premise of boson sampling, experimentally verifying that three-photon scattering amplitudes are given by the permanents of submatrices generated from a unitary describing a six-mode integrated optical circuit. We find the protocol to be robust, working even with the unavoidable effects of photon loss, non-ideal sources, and imperfect detection. Scaling this to large numbers of photons should be a much simpler task than building a universal quantum computer.
authors.affiliation: Centre for Engineered Quantum Systems, School of Mathematics and Physics, University of Queensland, Brisbane, Queensland 4072, Australia. m.a.broome@googlemail.com
authors.forename: Matthew A
authors.initials: MA
authors.lastname: Broome
authors.forename: Alessandro
authors.initials: A
authors.lastname: Fedrizzi
authors.forename: Saleh
authors.initials: S
authors.lastname: Rahimi-Keshari
authors.forename: Justin
authors.initials: J
authors.lastname: Dove
authors.forename: Scott
authors.initials: S
authors.lastname: Aaronson
authors.forename: Timothy C
authors.initials: TC
authors.lastname: Ralph
authors.forename: Andrew G
authors.initials: AG
authors.lastname: White