Berlin 2005 – wissenschaftliches Programm

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DY: Dynamik und Statistische Physik

DY 14: Complex Fluids

DY 14.9: Vortrag

Freitag, 4. März 2005, 17:30–17:45, TU H3010

Colloidal transport in 2d restricted geometries — •Michael Koeppl, Artur Erbe und Paul Leiderer — Universität Konstanz

Transport of electrons in two dimensions has been studied in electronic systems for decades. Typical examples are the quantum point contact or the quantum Hall effect in a semiconductor 2-dimensional electron gas (2DEG). In the non quantum mechanical regime of low densities and large structures compared to the electron wave function, colloidal systems can serve surprisingly good as a model system for electronic transport on the nanoscale. Since the fundamental interactions are not dominated by quantum effects, even systems like pedestrians show comparable dynamical behavior.

We use a videomicroscopy setup to investigate the transport of driven particles through topological restrictions and bottlenecks with sizes comparable to the particle diameter. The use of superparamagnetic colloids allows us to tune the plasma parameter of the system simply by ’turning a knob’ applying an external magnetic field. We report on lane formation of the particle trajectories due to interactions. Comparison of our colloidal transport measurements with simulations of electronic systems and traffic dynamics reveals good consistency.