Regensburg 2007 – scientific programme

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DY: Fachverband Dynamik und Statistische Physik

DY 24: Poster I

DY 24.38: Poster

Wednesday, March 28, 2007, 16:00–18:00, Poster D

Multiple time-delayed feedback control of noise-induced space-time patterns in a reaction-diffusion system — •Niels Majer, Grischa Stegemann, and Eckehard Schöll — Institut für Theoretische Physik, Technische Universität Berlin, Hardenbergstr. 36, 10623 Berlin

We study the influence of noise upon the nonlinear dynamics of current density patterns in a semiconductor nano-structure, and its control by multiple time delayed feedback methods. The investigated system is a double barrier resonant tunnelling diode described by a nonlinear reaction-diffusion model.

The parameters of the system are fixed at values below a Hopf bifurcation where the only stable state of the deterministic uncontrolled system is a spatially inhomogeneous "filamentary" steady state, and oscillating space-time patterns do not occur. The addition of weak Gaussian white noise to the system gives rise to spatially inhomogeneous oscillations.

We introduce a multiple time-delayed feedback control scheme (ETDAS) with a memory parameter R, and investigate its influence on the regularity of the noise induced dynamics under variation of R. The obtained results are explained using linear stability analysis.