## NJP: Observation of Autler-Townes effect in a dispersively dressed Jaynes-Cummings system

B. Suri, Z. K. Keane, R. Ruskov, Lev S. Bishop, Charles Tahan, S. Novikov, J. E. Robinson, F. C. Wellstood, B. S. Palmer

We report on the spectrum of a superconducting transmon device coupled to a planar superconducting resonator in the strong dispersive limit where discrete peaks, each corresponding to a different number of photons, are resolved. A thermal population of 5.474 GHz photons at an effective resonator temperature of T = 120 mK results in a weak n = 1 photon peak along with the n = 0 photon peak in the qubit spectrum in the absence of a coherent drive on the resonator. Two-tone spectroscopy using independent coupler and probe tones reveals an Autlerâ€“Townes splitting in the thermal n = 1 photon peak. The observed effect is explained accurately using the four lowest levels of the dispersively dressed qubitâ€“resonator system and compared to results from numerical simulations of the steady-state master equation for the coupled system.

Observation of Autler-Townes effect in a dispersively dressed Jaynes-Cummings system (http://iopscience.iop.org)