27. April 2017 , 17:00 - 18:30 Uhr

Glasses of Active Brownian Particles

Physikalisches Kolloquium

Vortrag von Prof. Thomas Voigtmann, Universität Düsseldorf, im Rahmen des Greifswalder Physikalischen Kolloquiums.

We discuss a dense system of active Brownian particles (ABP) as a simple model system to study the collective behavior of microswimmers. The particles posses a randomly changing internal sense of orientation and undergo Brownian dynamics modified by an ``active'' driving along that orientation.  The dynamics depends on two relevant parameters: the driving velocity $v_0$ and the rotational diffusion coefficient $D_r$. The latter is varied over a wide range to mimic the effects of persistence in the swimming direction.

Using the integration-through transients formalism and an extended mode-coupling theory of the glass transition (ABP-MCT), we study how the glass-transition dynamics depends on these parameters. We discuss under which circumstances the mapping of the system to an FDT-breaking one with an effective enhanced diffusivity (set by $v_0^2/D_r$) works and when it fails. In particular we address how the relaxation times and the glass transition point change (differently) upon varying the two parameters of the active motion.

Organisator

Prof. Dr. Thomas Ihle

Ort

Hörsaal Physik



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