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DY: Dynamik und Statistische Physik

DY 41: Nichtlineare Dynamik I

DY 41.5: Vortrag

Donnerstag, 14. März 2002, 11:00–11:15, H3

Chaotic spatio-temporal scenarios in a globally coupled reaction-diffusion system — •Jan Unkelbach, Andreas Amann, Pavel Rodin, and Eckehard Schöll — Institut für Theoretische Physik, TU Berlin, Hardenbergstr. 36 10623 Berlin

We study lateral pattern formation in a bistable semiconductor structure (double barrier resonant tunneling diode) with a Z-shaped current-voltage characteristic. The device is described by a nonlinear reaction-diffusion equation with a global coupling induced by the operation in a circuit with capacitance C and load resistance R. With the aid of an appropriate control circuit, conditions can be realized which are equivalent to a resistive circuit with negative R. In this case a menagery of spatio-temporal patterns exists (e.g. breathing or spiking current filaments) which exhibit different bifurcation scenarios leading to bistability between stationary uniform or nonuniform states and spatio-temporal oscillations, and to spatio-temporal chaos.