High-speed $R_{ZZ}$ gates in Kerr-cat qubits via fast-forward scaling

Kerr parametric oscillators can encode Kerr-cat qubits, whose biased-noise nature can reduce the hardware overhead required for fault-tolerant quantum computation. In a recently proposed $R_{ZZ}$-gate scheme for Kerr-cat qubits, a tunable coupler must be displaced while avoiding nonadiabatic excitat