title: Sideband transitions and two-tone spectroscopy of a superconducting qubit strongly coupled to an on-chip cavity.
abstract: Sideband transitions are spectroscopically probed in a system consisting of a Cooper pair box strongly but nonresonantly coupled to a superconducting transmission line resonator. When the Cooper pair box is operated at the optimal charge bias point, the symmetry of the Hamiltonian requires a two-photon process to access sidebands. The observed large dispersive ac-Stark shifts in the sideband transitions induced by the strong nonresonant drives agree well with our theoretical predictions. Sideband transitions are important in realizing qubit-photon and qubit-qubit entanglement in the circuit quantum electrodynamics architecture for quantum information processing.
authors.affiliation: Department of Applied Physics, Yale University, New Haven, Connecticut 06520, USA.
authors.forename: A
authors.initials: A
authors.lastname: Wallraff
authors.forename: D I
authors.initials: DI
authors.lastname: Schuster
authors.forename: A
authors.initials: A
authors.lastname: Blais
authors.forename: J M
authors.initials: JM
authors.lastname: Gambetta
authors.forename: J
authors.initials: J
authors.lastname: Schreier
authors.forename: L
authors.initials: L
authors.lastname: Frunzio
authors.forename: M H
authors.initials: MH
authors.lastname: Devoret
authors.forename: S M
authors.initials: SM
authors.lastname: Girvin
authors.forename: R J
authors.initials: RJ
authors.lastname: Schoelkopf