We study the quantum effect of chaos on dynamical tunneling in the driven pendulum. We analyze the avoided level crossing between the Floquet states associated with the chaotic part of the phase space and a member of the quasidegenerate doublet. As a result of the interaction, the doublet state whose Husimi distribution was initially localized on Kolmogorov-Arnold-Moser symmmetric islands exchanges its structure with the chaotic state. We investigate the implications of this kind of avoided crossing on the quantum dynamics of a wave packet initially centered on one of the symmetric islands.

• Received 14 February 1994

DOI:https://doi.org/10.1103/PhysRevA.50.1071