Cross resonance gate for a capacitively coupled two fluxonium device*

Cross resonance gate is an entangling gate widely used with transmon qubits for its 'all microwave' structure and no tunability requirements. Yet the weak anharmonicity of the transmon qubit puts some limitations on the CR gate such as the long gate duration. Fluxonium qubits on the other hand are promising candidates for better logic gate performances due to their large anharmonicity and longer coherence times: Application of the cross resonance gate on fluxoniums with fixed frequencies at the half flux quantum suggests shorter gate durations and less leakage to higher states. This work outlines an experimental scheme for calibration and realization of cross resonance gates on fluxonium devices. We will report our progress about the tune up procedures and the benchmarking for a cross resonance gate on a capacitively coupled two fluxonium device in a 3D cavity resonator.