Anomalous Microwave Response in YBCO Resonators beyond the Two-Level-System Model

Kaiwen Zheng, Nathan J. Johnson, Nathan T. Thobaben +5

We report the microwave response of coplanar-waveguide (CPW) resonators fabricated from $\mathrm{YB}{\mathrm{a}}_2\mathrm{C}{\mathrm{u}}_3{\mathrm{O}}_{7-\delta }$ (YBCO) thin films over temperatures from approximately $70~\math…