Resonance Assisted Tunneling in Floquet spin-J systems

We apply the theory of Resonance Assisted Tunneling (RAT) to a many-body quantum kicked system with a well-defined semiclassical limit. Using a quantum resonant condition, we identify eigenstates associated with classical resonances and compute their quasienergy splitting semiclassically. We distinguish two regimes: the first, where RAT predictions show excellent agreement with exact quantum results, and a second, where the splitting saturates and coincides with that of a harmonic oscillator with frequency determined by the classical oscillation of the resonance island. We quantify the perturbation strength above which RAT theory is no longer valid and analyze its scaling in the semiclassical limit, providing analytical expressions to estimate this upper bound.