Measurement Techniques for Superconducting Microwave Resonators Towards Quantum Device Applications

Superconducting qubits, though promising for both near-term problem-solving as well as the development of large-scale quantum computing systems, are limited in performance largely by materials-induced decoherence channels which are maximized at millikelvin temperatures, single photon powers, and microwave frequencies. Superconducting microwave resonators are ideal tools for measuring these materials losses due to their simplicity, well-understood behavior, and sensitivity to these same losses. In order to better understand and mitigate dominant qubit decoherence channels, accurate and precise characterization of superconducting microwave resonator performance is critical. In this paper, current measurement techniques for superconducting microwave resonators are discussed, including experimental set-up, error analysis, and cryogenic calibration of a vector network analyzer.