Tunable and switchable coupling between two superconducting resonators

Abstract

We realize a device allowing for tunable and switchable coupling between two frequency-degenerate superconducting resonators mediated by an artificial atom. For the latter, we utilize a persistent current flux qubit. We characterize the tunable and switchable coupling in frequency and time domain and find that the coupling between the relevant modes can be varied in a controlled way. Specifically, the coupling can be tuned by adjusting the flux through the qubit loop or by controlling the qubit population via a microwave drive. Our measurements allow us to find parameter regimes for optimal coupler performance and quantify the tunability range.

Stationary discrete solitons in a driven dissipative Bose-Hubbard chain

“…Moreover, a tunable coupling J has been achieved [37]. High reproducibility in the resonator bare frequencies, a necessary ingredient for building many-body arrays, also has been achieved [38].…”

Nonreciprocal quantum-state conversion between microwave and optical photons

“…When c, d are optical cavities, time-dependent coupling can be generated by connecting the cavities to other cavity modes or waveguides [33,53,54]. For cavities in both microwave and optical regimes, time-dependent interaction can also be generated by coupling the cavities to a quantum two-level system with tunable energy splitting, such as qubit and defect [55,56].…”

Scalable quantum computing model in the circuit-QED lattice with circulator function

“…There can be two possibilities to control the qubit-qubit interaction in scalable circuit-QED design. One is to control the resonator-resonator coupling by using a intervening dc-SQUID [28], flux qubit [37,38,39,40], Josephson ring modulator [41], or transmon qubit [42]. On the other hand one can try to tune the coupling between qubit and transmission line resonator by controlling the qubit frequency [29,30,31,32] or a coupling element inserted between qubit and resonator [33,34,35,36].…”