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DY: Fachverband Dynamik und Statistische Physik
DY 40: Posters II
DY 40.4: Poster
Donnerstag, 17. März 2011, 17:00–19:00, P3
Colloidal dynamics induced by phasonic drifts — •Justus Kromer1, Michael Schmiedeberg2, and Holger Stark1 — 1Institut für Theoretische Physik, Technische Universität Berlin, Germany — 2Weiche Materie, Heinrich-Heine-Universität Düsseldorf, Germany
Phasons are unique to quasicrystals. These are non-periodic solids which nevertheless possess long-range positional and orientational order. Phasons correspond to global rearrangements of atoms in quasicrystals. Like phonons they are hydrodynamic modes since they do not increase the free energy in the long wavelength limit. The properties of phasons are still intensively discussed in the field [1].
We study the dynamics of a colloidal adsorbate induced by a phasonic drift in a quasicristalline substrate potential using Brownian dynamics simulations. The drift changes the potential landscape continuously where minima disappear and new ones are created. After the system has reached a non-equilibrium steady state, we find that the colloids perform a characteristic stick-slip motion. By slipping into new minimas, the colloids rearrange and thereby realize the phasonic drift in the adsorbate. Although individual particles move in different directions, the colloids exhibit a net drift that sensitively depends on the direction and velocity of the phasonic drift. Our observations help to get a deeper insight into the properties of phasonic displacements in colloidal as well as in atomic quasicrystals.
[1] C. L. Henley, M. de Boissieu, and W. Steurer, Philos. Mag. 86, 1131 (2006).