Tunable and Switchable Coupling Between Two Superconducting Resonators

TL;DR

This paper demonstrates a device with tunable and switchable coupling between two superconducting resonators, controlled via a flux qubit, enabling dynamic control for quantum information applications.

Contribution

The authors introduce a novel device that achieves tunable and switchable coupling between resonators using a persistent current flux qubit, with detailed characterization.

Findings

Coupling can be tuned by adjusting flux or saturating the qubit.

Optimal switch performance depends on qubit drive power.

Coupling variation is controllable in frequency and time domains.

Abstract

We realize a device allowing for tunable and switchable coupling between two 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 saturating the qubit. Our time domain measurements allow us to find parameter regimes for optimal switch performance with respect to qubit drive power and the dynamic range of the resonator input power.