title: Fast accurate state measurement with superconducting qubits.
abstract: Faster and more accurate state measurement is required for progress in superconducting qubit experiments with greater numbers of qubits and advanced techniques such as feedback. We have designed a multiplexed measurement system with a bandpass filter that allows fast measurement without increasing environmental damping of the qubits. We use this to demonstrate simultaneous measurement of four qubits on a single superconducting integrated circuit, the fastest of which can be measured to 99.8% accuracy in 140 ns. This accuracy and speed is suitable for advanced multiqubit experiments including surface-code error correction.
authors.affiliation: Department of Physics, University of California, Santa Barbara, California 93106-9530, USA.
authors.forename: Evan
authors.initials: E
authors.lastname: Jeffrey
authors.affiliation: Department of Physics, University of California, Santa Barbara, California 93106-9530, USA.
authors.forename: Daniel
authors.initials: D
authors.lastname: Sank
authors.affiliation: Department of Physics, University of California, Santa Barbara, California 93106-9530, USA.
authors.forename: J Y
authors.initials: JY
authors.lastname: Mutus
authors.affiliation: Department of Physics, University of California, Santa Barbara, California 93106-9530, USA.
authors.forename: T C
authors.initials: TC
authors.lastname: White
authors.affiliation: Department of Physics, University of California, Santa Barbara, California 93106-9530, USA.
authors.forename: J
authors.initials: J
authors.lastname: Kelly
authors.affiliation: Department of Physics, University of California, Santa Barbara, California 93106-9530, USA.
authors.forename: R
authors.initials: R
authors.lastname: Barends
authors.affiliation: Department of Physics, University of California, Santa Barbara, California 93106-9530, USA.
authors.forename: Y
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Department of Physics, University of California, Santa Barbara, California 93106-9530, USA.
authors.forename: Z
authors.initials: Z
authors.lastname: Chen
authors.affiliation: Department of Physics, University of California, Santa Barbara, California 93106-9530, USA.
authors.forename: B
authors.initials: B
authors.lastname: Chiaro
authors.affiliation: Department of Physics, University of California, Santa Barbara, California 93106-9530, USA.
authors.forename: A
authors.initials: A
authors.lastname: Dunsworth
authors.affiliation: Department of Physics, University of California, Santa Barbara, California 93106-9530, USA.
authors.forename: A
authors.initials: A
authors.lastname: Megrant
authors.affiliation: Department of Physics, University of California, Santa Barbara, California 93106-9530, USA.
authors.forename: P J J
authors.initials: PJ
authors.lastname: O'Malley
authors.affiliation: Department of Physics, University of California, Santa Barbara, California 93106-9530, USA.
authors.forename: C
authors.initials: C
authors.lastname: Neill
authors.affiliation: Department of Physics, University of California, Santa Barbara, California 93106-9530, USA.
authors.forename: P
authors.initials: P
authors.lastname: Roushan
authors.affiliation: Department of Physics, University of California, Santa Barbara, California 93106-9530, USA.
authors.forename: A
authors.initials: A
authors.lastname: Vainsencher
authors.affiliation: Department of Physics, University of California, Santa Barbara, California 93106-9530, USA.
authors.forename: J
authors.initials: J
authors.lastname: Wenner
authors.affiliation: Department of Physics, University of California, Santa Barbara, California 93106-9530, USA.
authors.forename: A N
authors.initials: AN
authors.lastname: Cleland
authors.forename: John M
authors.initials: JM
authors.lastname: Martinis