Fig. 4
From: Realisation of high-fidelity nonadiabatic CZ gates with superconducting qubits
CCZ result. a–d for simulation and e for experiment. a Qubits energy level as a function of qubit 3 detuning. At around 160 MHz detuning of qubit 3, the |111〉, |021〉, and |030〉 states interact strongly (interaction point). b CCZ pulse applied to qubit 3, which obtains fidelity of 99.3%. c Evolution of each state under CCZ pulse. Dotted (solid) lines show the evolution when the initial state is |110〉 (|111〉). Both black lines (dotted and solid) hovering near unity for the entire pulse duration the means that pulse can be analysed by separating the evolution into two (nearly) independent subspaces. Note that |110〉 interacts strongly with |020〉, and that |111〉 interacts strongly with |021〉 and |030〉. |111〉 also interacts slightly with |120〉 in the |111〉-|021〉-|030〉-|120〉 subspace. d State population in the eigenstate during the pulse for |110〉 and |111〉 being input. e Process tomography of CCZ in experiment. The clear bars represent the ideal matrix and the solid bars represent the experimental matrix
