Berlin 2018 – wissenschaftliches Programm
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DY: Fachverband Dynamik und Statistische Physik
DY 71: Poster: Noneq. Stat. Phys., Stoch. Thermo, Brownian Dyn.
DY 71.13: Poster
Donnerstag, 15. März 2018, 15:30–18:00, Poster A
Heterogeneous diffusion in comb-like structures — •Trifce Sandev1,2,3, Alexander Schulz4, Holger Kantz4, and Alexander Iomin5 — 1Ss. Cyril and Methodius University in Skopje, Macedonia — 2RSD, Skopje, Macedonia — 3MANU, Skopje, Macedonia — 4MPIPKS Dresden, Germany — 5Technion, Haifa, Israel
We consider diffusion with a position dependent diffusion coefficient along a backbone in different comb and fractal grid structures. The comb structures consist of main channel (backbone) and trapping fingers. Diffusion along the backbone, which is chosen to be the x-direction, occurs only at y=0, and the fingers play the role of traps. This is a particular example of geometrical traps, where a particle, moving along the backbone, can get trapped inside a finger of the comb, where it diffuses in the y-direction, until it returns by chance to the backbone. Such behaviour of the particle can be described in the framework of the continuous time random walk theory, where the returning probability scales similarly to t−1/2, and the waiting times are distributed according t−3/2. We present analytical results for the mean squared displacement for the power-law position dependent diffusion coefficient along the backbone. We observe various diffusion regimes, such as subdiffusion, superdiffusion, hyperdiffusion, as well as stochastic localization. Our analytical results are in a good agreement with the numerical analysis of this heterogeneous transport, obtained in the framework of the Langevin equations description [1].
[1] T. Sandev, A. Schulz, H. Kantz, and A. Iomin, Chaos Solitons & Fractals, DOI: 10.1016/j.chaos.2017.04.041 (2017).