  We propose a protocol for the preparation of high-fidelity entangled cat
states with composite pulses. The physical model contains two Kerr-nonlinear
resonators and a cavity. By properly designing the parameters, each
Kerr-nonlinear resonator is confined in the cat-state subspace and the
entangled cat states can be generated efficiently. We introduce composite
two-photon drives with multiple amplitudes and frequencies to improve the
fidelity of the entangled cat states in the presence of parameter errors. The
performance of the protocol is estimated by taking into account the parametric
errors and decoherence. Numerical simulation results show that the protocol is
insensitive to timing error and detuning error, and has strong robustness to
decoherence. We hope the protocol may provide a method for preparing stable
entangled cat states.
