title: Randomized benchmarking of multiqubit gates.
abstract: We describe an extension of single-qubit gate randomized benchmarking that measures the error of multiqubit gates in a quantum information processor. This platform-independent protocol evaluates the performance of Clifford unitaries, which form a basis of fault-tolerant quantum computing. We implemented the benchmarking protocol with trapped ions and found an error per random two-qubit Clifford unitary of 0.162±0.008, thus setting the first benchmark for such unitaries. By implementing a second set of sequences with an extra two-qubit phase gate inserted after each step, we extracted an error per phase gate of 0.069±0.017. We conducted these experiments with transported, sympathetically cooled ions in a multizone Paul trap-a system that can in principle be scaled to larger numbers of ions.
authors.affiliation: National Institute of Standards and Technology, 325 Broadway, Boulder, Colorado 80305, USA. john.gaebler@nist.gov
authors.forename: J P
authors.initials: JP
authors.lastname: Gaebler
authors.forename: A M
authors.initials: AM
authors.lastname: Meier
authors.forename: T R
authors.initials: TR
authors.lastname: Tan
authors.forename: R
authors.initials: R
authors.lastname: Bowler
authors.forename: Y
authors.initials: Y
authors.lastname: Lin
authors.forename: D
authors.initials: D
authors.lastname: Hanneke
authors.forename: J D
authors.initials: JD
authors.lastname: Jost
authors.forename: J P
authors.initials: JP
authors.lastname: Home
authors.forename: E
authors.initials: E
authors.lastname: Knill
authors.forename: D
authors.initials: D
authors.lastname: Leibfried
authors.forename: D J
authors.initials: DJ
authors.lastname: Wineland