Multilevel Effects in a Driven Generalized Rabi Model

• DOI: 10.1007/s10909-018-1857-8
• Publication Date: 2018-01-30T12:51:37Z
• Authors: I. Pietikäinen; S. Danilin; K. S. Kumar; J. Tuorila; G. S. Paraoanu
• Keywords: Quantum Physics; ta114; Floquet method; Condensed Matter - Mesoscale and Nanoscale Physics; Mesoscale and Nanoscale Physics (cond-mat.mes-hall); 8. Economic growth; 0103 physical sciences; Multilevel effects; FOS: Physical sciences; Quantum Physics (quant-ph); 01 natural sciences; Quantum Rabi model; 3. Good health

We study numerically the onset of higher-level excitations and resonance frequency shifts in the generalized multilevel Rabi model with dispersive coupling under strong driving. The response to a weak probe is calculated using the Floquet method, which allows us to calculate the probe spectrum and extract the resonance frequency. We test our predictions using a superconducting circuit consisting of transmon coupled capacitively to a coplanar waveguide resonator. This system is monitored by a weak probe field, and at the same time driven at various powers by a stronger microwave tone. We show that the transition from the quantum to the classical regime is accompanied by a rapid increase of the transmon occupation and, consequently that the qubit approximation is valid only in the extreme quantum limit.<br/>12 pages, 4 figures<br/>