Berlin 2008 – scientific programme

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DY: Fachverband Dynamik und Statistische Physik

DY 17: Poster I

DY 17.35: Poster

Tuesday, February 26, 2008, 16:00–18:00, Poster C

Hamiltonian dynamics in a one-dimensional, spatially quenched random potential — •Ines Hartwig — Technische Universität Chemnitz

The Chirikov-Taylor standard map is modified by introducing a one-dimensional quenched random -- yet analytic -- potential. Besides having Gaussian autocorrelation, the potential also is Gaussian distributed. In order to define a fundamental cell in Hamiltonian phase space, the potential is made periodic. Finite-size effects created by this periodicity are considered.

The dependence of phase space structures and transport properties both on the period of the potential and the perturbation strength of the map are investigated. Diffusion exponents for transport in the momentum as well as the spatial coordinate are determined and compared to the standard map under corresponding perturbation. Enhanced transport for the random case is shown.

Crude estimates for the critical perturbation strenghts for the destruction of the last KAM-curve are found. Their frequency distribution over many realizations of the random potential is presented.