Superconducting resonator single-photon spectroscopy through electromagnetically induced transparency

Investigation of intrinsic loss mechanism of superconducting resonator is a crucial task toward the study of the constituent material as well as application in quantum information process. Typical approach from transmission or reflection spectrum is however subjected to Fano-effect, which can induce systematic errors in discerning intrinsic and external losses. To avoid such requires under-coupled resonator and consequently sets a challenge when a large quality factor is expected and measurements at single-photon power levels is required. In this work, we propose and demonstrate a new approach with additional qubit coupled dispersively. Inducing electromagnetically induced transparency (EIT) in qubit spectrum, we can extract the resonator’s single-photon internal linewidth. Our work demonstrates a practical application of EIT for device spectroscopy.