Coplanar silicon/aluminum resonators with internal quality factor above 2M: measurements*

High quality factor superconducting coplanar waveguide microwave resonators provide a well established technique for qubits control and readout in quantum processors based on circuit QED and hybrid devices. Along with many fabrication issues in such devices, packaging, electromagnetic shielding and filtering, as well as advanced cryogenic setup play crucial role. In this work, we focused on sample holders design and materials simulations, verified by superconducting resonators quality factor and qubits lifetime cryogenic measurements. The impact of cryogenic setups with various shielding and filtering techniques is considered. As the result of packaging and cryogenic setup optimization we demonstrate the robust measurements of superconducting coplanar waveguide resonators with internal quality factor over 2 millions and tunable X-mon qubits with coherence up to 100 us.

*Devices were fabricated at the BMSTU Nanofabrication Facility (Functional Micro/Nanosystems, FMNS REC, ID 74300).