Dresden 2006 – wissenschaftliches Programm

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DY: Dynamik und Statistische Physik

DY 51: Non-Linear Stochastic Systems

DY 51.5: Vortrag

Freitag, 31. März 2006, 12:30–12:45, H\"UL 186

Controlling noise-induced oscillations by time-delayed feedback — •Clemens v. Loewenich and Hartmut Benner — Institut für Festkörperphysik, Technische Universität Darmstadt

Noise-induced oscillations may be observed in a van der Pol oscillator in the regime just below the Hopf bifurcation, where the noisefree system still has a stable fixed point. It was shown analytically and numerically that these oscillations can be controlled by time-delayed feedback, which allows to maximize their correlation time on variation of delay time and feedback strength [1,2].

In order to check the validity of these theoretical findings we made experimental investigations on a van der Pol type electronic circuit. In fact, we observed the occurrence of noise-induced oscillations and studied the dependence between correlation time, noise and feedback strength. Discrepancies between experimental and theoretical data could be attributed to the limited bandwidth of our experimental noise source in contrast to the white noise assumption of the model.

[1] N. B. Janson et al., Phys. Rev. Lett. 93, 010601 (2004)

[2] J. Pomplun et al., Europhys. Lett. 71, 366 (2005)