Regensburg 2007 – scientific programme

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DY: Fachverband Dynamik und Statistische Physik

DY 30: Poster II

DY 30.47: Poster

Thursday, March 29, 2007, 16:00–18:00, Poster D

Non-linear conductivity effects in disordered systems: a theoretical approach — •Lars Lühning and Andreas Heuer — Institut für Physikalische Chemie, Westfälische Wilhelms-Universität Münster, Germany

The nonlinear conductivity effects of thin ionic conductors under the influence of ac- and dc electric fields are studied numerically and analytically using a regular hopping model with a characteristic hopping distance representing the typical distance between adjacent ionic sites.

Here we analyze a single-particle hopping model. The transition rates are deduced from a sequence of randomly distributed trapping sites using periodic boundary conditions. An analytical expression for the stationary current under a constant and periodic force in one dimension is given and verified by numerical calculations. Numerical results for the stationary current in two and three dimensions are also presented. It turns out that the stationary current depends on the sample thickness. Interestingly, the first corrections to the linear response display a non-trivial behavior in the thermodynamic limit.