Experimental Tools for A/B Materials Testing Towards High-Coherence Superconducting Quantum Devices*

Materials-induced losses define the coherence ceiling for state-of-the-art superconducting qubits, as well as for other superconducting devices operating in the millikelvin, single-photon regime. A myriad of difficulties arise when isolating loss contributions from particular materials and interfaces in devices with complex geometries and measurement procedures in a rapidly evolving field. Harnessing the power of simple A/B testing for materials engineering would allow immediate performance improvements in superconducting devices, but requires a new set of standard experimental tools. In this talk, we propose some of these enabling tools, including a standard resonator mask set for probing the loss contributions of device interfaces, an open-source resonator data analysis codebase, and a framework for more rigorous error analysis of materials loss parameters.