Magnetic-Field-Resilient Superconducting Coplanar-Waveguide Resonators for Hybrid Circuit Quantum Electrodynamics Experiments

Superconducting coplanar waveguide resonators that can operate in strong magnetic fields are important for a variety of high-frequency superconducting devices. Magnetic fields degrade resonator performance by creating Abrikosov vortices that cause resistive losses and frequency fluctuations, or suppress the superconductivity entirely. To mitigate these effects, the authors investigate how device geometry and lithographically defined artificial defects can control vortex dynamics. These techniques allow the resonators to retain single-photon quality factors of about 10⁵ at B_∥ {} 6 T, for fast charge readout of a gate-defined double quantum dot at B_∥ = 1 T.