
07/04 11:00
Pavol Neilinger (Bratislava)
LandauZenerStückelbergMajorana interference and Rabilike oscillations in circuit QED
A linear sweep of a quantum twolevel system through its avoided energy level crossing leads to nonadiabatic transition at the avoided crossing. This transition from ground to excited state is known as the LandauZener tunneling. A periodical sweeping of the qubit state through the avoided level crossing induces subsequent Landau−Zener transitions leading to LandauZenerStückelbergMajorana (LZSM) interference. We report on experimental observation of LZSM interference patterns through the amplification/attenuation of a probe signal in a driven twolevel quantum system, coupled to a microwave resonator under an external offresonant drive. The experimental data are explained by the interaction of the probe signal with Rabilike oscillations, a reminiscent of the oscillations of level occupation in resonantly driven twolevel quantum systems, the wellknown Rabi oscillations. The Rabilike oscillations are created by constructive interference of LZSM transitions during the driving period of the qubit. Furthermore, a numerical computation of the average photon number in the resonator is carried out on a driven twolevel system strongly coupled to a singlemode radiation field of a quantized resonator, creating a multilevel qubitresonator system. The obtained LZSM interference patterns in the average photon number are compared with the analytical approach of the Rabilike oscillations and good correspondence is found. Thus, we propose, similarly to the use of Rabi oscillations, to exploit the Rabilike oscillations for the processing of microwave quantum signals.

