Loss Characterization in Superconducting Resonators*

Uniquely characterizing loss from two-level systems (TLS) in dielectric materials in coplanar waveguide resonators is challenging due to the nearly proportional scaling of the electric field participation in response to changes in geometry and anisotropic trench depth [1]. We tailor our resonator design and fabrication process to focus the participation into specific dielectric regions such that we can characterize the specific loss tangent of each dielectric [2]. In this talk, we characterize the change in overall quality factor and dielectric-specific loss tangent arising from specific changes to the fabrication process.
[1] Calusine, Appl. Phys. Lett. 112, 062601 (2018)
[2] Woods, Phys. Rev. Appl. 12, 014012 (2019)