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DY: Dynamik und Statistische Physik

DY 19: Poster II

DY 19.29: Poster

Donnerstag, 20. März 1997, 09:30–12:30, Z

Quantum manifestations of Chaotic Scattering in the Presence of KAM Tori — •W. Schirmacher¹, M. Eichengrün¹, and W. Breymann² — ¹Phys. Dept. E13, TU München — ²Institut für Physik, Universit"at Basel

We investigate the semiclassical scattering amplitude for systems, where the classical dynamics is non-hyperbolic, i. e., where islands of KAM trajectories exist in an otherwise chaotic phase space. With the help of semiclassical calculations for the three-disk billiard in an external magnetic field, in which a hyperbolic- non-hyperbolic transition is observed as a function of the field strength, we show that the "’stickiness"’ of the KAM tori leads to a much slower decrease of the survival probability, as compared with the hyperbolic case. This is reflected by a much narrower shape of the energy correlation function. However, we also find that the algebraic asymptotic decay of the survival probability in the non-hyperbolic case is not important for the quantum fluctuations.