Dumbbell diffusion in a spatially periodic potential

Bammert, Jochen; Schreiber, Steffen; Zimmermann, Walter

Dumbbell diffusion in a spatially periodic potential

Authors

Bammert, Jochen

Schreiber, Steffen

Zimmermann, Walter

Description

We present a numerical investigation of the Brownian motion and diffusion of a dumbbell in a two-dimensional periodic potential. Its dynamics is described by a Langevin model including the hydrodynamic interaction. With increasing values of the amplitude of the potential we find along the modulated spatial directions a reduction of the diffusion constant and of the impact of the hydrodynamic interaction. For modulation amplitudes of the potential in the range of the thermal energy the dumbbell diffusion exhibits a pronounced local maximum at a wavelength of about 3/2 of the dumbbell extension. This is especially emphasized for stiff springs connecting the two beads.
4 pages, 7 figures, published in Phys. Rev. E (2008)