Two-tone spectroscopy of high-frequency quantum circuits with a Josephson emitter
A. Peugeot, H. Riechert, S. Annabi, Léo Balembois, M. Villiers, Emmanuel Flurin, J. Griesmar, E. Arrighi, Jean-Damien Pillet, Landry Bretheau · Physical Review Applied · 2024
We perform two-tone spectroscopy on quantum circuits, where high-frequency radiation is generated by a voltage-biased superconductor-normal-superconductor Josephson junction and detection is carried out by an ancillary microwave resonator. We implement this protocol on two different systems, a transmon qubit and a $\ensuremath{\lambda}/4$ resonator. We demonstrate that this two-tone Josephson spectroscopy operates well into the millimeter-wave band, reaching frequencies larger than 80 GHz, and is well suited for probing highly coherent quantum systems.