Cantori barriers in the excitation of a diatomic molecule by chirped pulses

We present a nonlinear dynamical study of a diatomic molecule under the int eraction of chirped pulses. The step-like dissociation probability with res pect to the initial vibrational states reflects the cantori barriers during the excitation process. The correspondence between classical and quantum c antori barriers is shown through classical phase trajectory and quantum Hus imi distribution function. According to the results, the quantum suppressio n of classical dissociation in molecular excitation by chirped pulse disapp ears at some field parameters.