Tunable resonant and nonresonant interactions between a phase qubit and LC resonator
Michael S. Allman
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.
Tunable resonant and nonresonant interactions between a phase qubit and LC resonator, Physical Review Letters, [online], https://doi.org/10.1103/PhysRevLett.112.123601
(Accessed February 28, 2024)