Enhanced Diffusion of a Needle in a Planar Course of Point Obstacles

Felix Höfling; Erwin Frey; Thomas Franosch

doi:10.1103/physrevlett.101.120605

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arXiv · 0806.1138

Enhanced Diffusion of a Needle in a Planar Course of Point Obstacles

Felix Höfling·Erwin Frey·Thomas Franosch

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Abstract

The transport of an infinitely thin, hard rod in a random, dense array of point obstacles is investigated by molecular dynamics simulations. Our model mimics the sterically hindered dynamics in dense needle liquids. The center-of-mass diffusion exhibits a minimum, and transport becomes increasingly fast at higher densities. The diffusion coefficient diverges according to a power law in the density with an approximate exponent of 0.8. This observation is connected with a new divergent time scale, reflected in a zig-zag motion of the needle, a two-step decay of the velocity-autocorrelation function, and a negative plateau in the non-Gaussian parameter.

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Felix Höfling, Erwin Frey, Thomas Franosch. 2008-08-26. Enhanced Diffusion of a Needle in a Planar Course of Point Obstacles. https://doi.org/10.1103/physrevlett.101.120605

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