arXiv:1307.6032 · Superconductor Science and Technology
Charge qubit driven via the Josephson nonlinearity
Jani Tuorila, Matti Silveri, Mika E. T. Sillanpää, Erkki Thuneberg, Yuriy Makhlin, Pertti Juhani Hakonen
Abstract
We study the novel nonlinear phenomena that emerge in a charge qubit due to the interplay between a strong microwave flux drive and a periodic Josephson potential. We first analyse the system in terms of the linear Landau–Zener–Stückelberg model, and show its inadequacy in a periodic system with several Landau–Zener crossings within a drive period. Experimentally, we probe the quasienergy levels of the driven qubit with an L C cavity, which requires the use of linear response theory. We show also that our numerical calculations are in good agreement with the experimental data.