Detailed modelling of the susceptibility of a thermally populated, strongly driven circuit-QED system
Anton Frisk Kockum, Martin O. Sandberg, G¿ran Johansson, David P. Pappas
We present measurements and modelling of the susceptibility of a 2D microstrip cavity coupled to a driven transmon qubit. We are able to fit the response of the cavity to a weak probe signal with high accuracy in the strong coupling, low detuning, i.e., non-dispersive, limit over a wide bandwidth. The observed spectrum is rich in multi-photon processes for the doubly dressed transmon. These features are well explained by including the higher transmon levels in the driven Jaynes-Cummings model and solving the full master nist-equation to calculate the susceptibility of the cavity.
Journal of Physics B-Atomic Molecular and Optical Physics