Sideband transitions and two-tone spectroscopy of a superconducting qubit strongly coupled to an on-chip cavity.
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.
Wallraff
A
A
Department of Applied Physics, Yale University, New Haven, Connecticut 06520, USA.
Schuster
D I
DI
Blais
A
A
Gambetta
J M
JM
Schreier
J
J
Frunzio
L
L
Devoret
M H
MH
Girvin
S M
SM
Schoelkopf
R J
RJ