The stickiness effect of hydrogen atom evidenced by stable and unstable manifolds.

In this paper, we investigated the stickiness effect of the Hamilton system of the Hydrogen atom exposed to intense laser field. Even for the one electron system, its Poincare surface of section shows the chaotic and regular parts due to the laser field which can be explained by KAM (Kolmogorov, Arnold, and Moser) theory. The unstable periodic orbit (UPO) in chaotic "sea" was located by variational method and the corresponding stable manifold (SM) and unstable manifold (UM) of the UPO were numerically calculated. It was shown that the dynamics of ionization of the one electron system is governed by the UPO. On one hand, the SM of UPO is well superposed with the recurrence plot, which indicates that the SM overlaps just the stable initial points in phase space. On the other hand, the UM is almost coincide with the densely distributed points on Poincare surface of section. This indicated that the UM is just the ionization channels of the trajectories driven by laser field. Furthermore, the survival probabilities of different regions which gradually cross the UM and SM tangential flow nearby the stable island are studied. They obey an algebraic decaying law. The similar decay trend are also observed on different regions on the UM which possess almost the same decay parameters with that of region nearby the UPO. These observations confirmed that the stability properties of UPO play very important role in the stickiness effect of the phase space nearby the KAM stable islands. [ABSTRACT FROM AUTHOR]