Berlin 2018 – scientific programme

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DY: Fachverband Dynamik und Statistische Physik

DY 29: Particulate Matter: From microscopic interactions to collective motion (joint session DY/CPP)

DY 29.1: Talk

Tuesday, March 13, 2018, 14:00–14:15, EB 107

Onset of anomalous diffusion in colloids confined to quasimonolayers — •Martin Oettel¹, Johannes Bleibel¹, and Alvaro Dominguez² — ¹Institut für Angewandte Physik, Universität Tübingen — ²Fisica Teorica, Universidad de Sevilla

It has been recently shown that a colloidal monolayer, e.g., formed at a fluid interface or by means of a suitable confining potential, exhibits anomalous collective diffusion: diffusion becomes accelerated as signalled by a 1/k–divergence of the wavenumber–dependent collective diffusion coefficient. This is a consequence of the hydrodynamic interactions mediated by the three-dimensional (3D) ambient fluid when the particles are confined to reside on a two-dimensional (2D) manifold. We study theoretically and with numerical simulations the crossover from normal to anomalous diffusion as the particles are, in real systems, confined by a 3D external potential and thus have the possibility to fluctuate out of the 2D manifold, thus forming a quasimonolayer. In essence, we always find anomalous diffusion on lateral length scales larger than the confinement width.