Phase-controlled coherent population trapping in superconducting quantum circuits*
Cheng Guang-Linga)†, Wang Yi-Pinga), Chen Ai-Xia),b)‡
       
(a) A fluxonium circuit model, consisting of a small Josephson junction and a large Josephson junction array, is capacitively coupled to a transmission line. (b) For the fluxonium qubit, the transition frequencies of the lowest eigenstates, and (c) the charge matrix elements as a function of the flux bias Φ ext/ Φ , where the parameters are from the experiments with E C = 2.5 GHz, E L = 0.52 GHz, E J =9.0 GHz. Here we focus on the case of Φ ext/ Φ = 0.43, indicated by the dotted vertical line, where the condition | N 13| = | N 23| is obtained.