title: RF-driven Josephson bifurcation amplifier for quantum measurement.
abstract: We have constructed a new type of amplifier whose primary purpose is the readout of superconducting quantum bits. It is based on the transition of a rf-driven Josephson junction between two distinct oscillation states near a dynamical bifurcation point. The main advantages of this new amplifier are speed, high sensitivity, low backaction, and the absence of on-chip dissipation. Pulsed microwave reflection measurements on nanofabricated Al junctions show that actual devices attain the performance predicted by theory.
authors.affiliation: Departments of Applied Physics and Physics, Yale University, New Haven, Connecticut 06520-8284, USA.
authors.forename: I
authors.initials: I
authors.lastname: Siddiqi
authors.forename: R
authors.initials: R
authors.lastname: Vijay
authors.forename: F
authors.initials: F
authors.lastname: Pierre
authors.forename: C M
authors.initials: CM
authors.lastname: Wilson
authors.forename: M
authors.initials: M
authors.lastname: Metcalfe
authors.forename: C
authors.initials: C
authors.lastname: Rigetti
authors.forename: L
authors.initials: L
authors.lastname: Frunzio
authors.forename: M H
authors.initials: MH
authors.lastname: Devoret