Fig. 4: Qubit spectroscopy and Landau–Zener–Stückelberg interference.
From: Large flux-mediated coupling in hybrid electromechanical system with a transmon qubit
a Measurement of the qubit spectrum with the detuning of spectroscopy tone Δqs = ωs − ωq, where ωs is the spectroscopy frequency. The mechanical drive signal is varied from 1 to 10 mV in steps of 1 mV (bottom to top). The Rabi flop rate ΩR/2π is about 3 MHz. Apart from the primary splitting, weak fringes arising from the Landau–Zener–Stückelberg interference are visible. Dotted lines are added as guide to the eye. b The solid lines show the results from the Master equation. The dotted lines show the results from semi-classical calculation. Clearly, the calculations performed using the Master equation match the experimental results better. The qubit frequency deviation is changed from 7 MHz to 70 MHz in steps of 7 MHz (bottom to top). A qubit relaxation rate of 2 MHz, and a pure dephasing rate of 4 MHz is used to calculate the qubit spectrum. In both panels, the probe transmission corresponding to the lowest mechanical drive is normalized to one, and an offset of 0.125 has been added successively.
