Dresden 2006 – wissenschaftliches Programm
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SYSS: Structure Formation and Self-Organization in non-equilibrium Systems
SYSS 1: Structure Formation and Self-Organization in non-equilibrium Systems I
SYSS 1.1: Vortrag
Donnerstag, 30. März 2006, 09:30–09:45, BAR Sch\"o
Ferrosolitons — •Reinhard Richter1 and Igor Barashenkov2 — 1Experimentalphysik 5, Universität Bayreuth, D-95440 Bayreuth, Germany — 2University of Capetown, Rondebosch 7700, South Africa
Solitary structures in two dimensions have been mostly confined to vortices in superconductors and superfluids on one hand and dissipative solitons in nonequilibrium systems on the other. While the stability of the former is due to their nontrivial topology, the latter are believed to be stable thanks to the balance of strong dissipation and energy gain. Neither of these stabilisation principles could be at work for localised patterns on the surface of a horizontal layer of ferrofluid: this is a lossless system with no special topology. Nevertheless, we have recently discovered stable solitary spikes in the bistable regime of the Rosensweig instability [1]. These ferrosolitons can be generated by a local magnetic field application, or simply by mechanical perturbation of the flat surface. Their stability can be explained in part by the locking of the expanding front to the wavelength of the coexisting periodic pattern [2]. We investigate the profiles of ferrosolitons, measured by means of radioscopy [3] and analyze the locked wavefront. The ferrosolitons have oscillatory tails, which become wider as the magnetic induction is increased. We compare the measured profiles with analytical and numerical estimations.
[1] Reinhard Richter, and I.V. Barashenkov, Phys. Rev. Lett. 94 184503-1 (2005).
[2] Y. Pomeau, Physica D (Amsterdam) 23, 3 (1986).
[3] Reinhard Richter, and Jürgen Bläsing, Rev. Sci. Instrum. 72, 1729 (2001).