Probing strongly driven and strongly coupled superconducting qubit-resonator system

Abstract

We investigated a strongly driven qubit strongly connected to a quantum resonator. The measured system was a superconducting flux qubit coupled to a coplanar-waveguide resonator which is weakly coupled to a probing feedline. This hybrid qubit-resonator system was driven by a magnetic flux and probed with a weak probe signal through the feedline. We observed and theoretically described the quantum interference effects, deviating from the usual single-qubit Landau-Zener-St\"{u}ckelberg-Majorana interferometry, because the strong coupling distorts the qubit energy levels.