Tunable resonant and nonresonant interactions between a phase qubit and LC resonator.
We use a flux-biased radio frequency superconducting quantum interference device (rf SQUID) with an embedded flux-biased direct current SQUID to generate strong resonant and nonresonant tunable interactions between a phase qubit and a lumped-element resonator. The rf SQUID creates a tunable magnetic susceptibility between the qubit and resonator providing resonant coupling strengths from zero to near the ultrastrong coupling regime. By modulating the magnetic susceptibility, nonresonant parametric coupling achieves rates >100  MHz. Nonlinearity of the magnetic susceptibility also leads to parametric coupling at the subharmonics of the qubit-resonator detuning.
National Institute of Standards and Technology, 325 Broadway Street, Boulder, Colorado 80305-3328, USA.
M S
MS
Allman
National Institute of Standards and Technology, 325 Broadway Street, Boulder, Colorado 80305-3328, USA.
J D
JD
Whittaker
National Institute of Standards and Technology, 325 Broadway Street, Boulder, Colorado 80305-3328, USA.
M
M
Castellanos-Beltran
National Institute of Standards and Technology, 325 Broadway Street, Boulder, Colorado 80305-3328, USA.
K
K
Cicak
National Institute of Standards and Technology, 325 Broadway Street, Boulder, Colorado 80305-3328, USA.
F
F
da Silva
National Institute of Standards and Technology, 325 Broadway Street, Boulder, Colorado 80305-3328, USA.
M P
MP
DeFeo
National Institute of Standards and Technology, 325 Broadway Street, Boulder, Colorado 80305-3328, USA.
F
F
Lecocq
National Institute of Standards and Technology, 325 Broadway Street, Boulder, Colorado 80305-3328, USA.
A
A
Sirois
National Institute of Standards and Technology, 325 Broadway Street, Boulder, Colorado 80305-3328, USA.
J D
JD
Teufel
National Institute of Standards and Technology, 325 Broadway Street, Boulder, Colorado 80305-3328, USA.
J
J
Aumentado
National Institute of Standards and Technology, 325 Broadway Street, Boulder, Colorado 80305-3328, USA.
R W
RW
Simmonds