Berlin 2008 – wissenschaftliches Programm
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DY: Fachverband Dynamik und Statistische Physik
DY 4: Brownian motion and transport
DY 4.7: Vortrag
Montag, 25. Februar 2008, 15:45–16:00, MA 004
Diffusive Processes on Fractals — •Janett Prehl1, Do H. N. Anh1, Karl Heinz Hoffmann1, and Sujata Tarafdar2 — 1Institut für Physik, Technische Universität Chemnitz, D-09107 Chemnitz — 2Condensed Matter Physics Research Center, Jadaypur University, Kolkata 700 032, India
Anomalous diffusion processes are of great interest in natural science as well as in many applications, like diffusion in disordered media such as porous rocks, cements, or biological tissues. In order to model anomalous diffusion random walks on regular fractals or the master equation approach are usually used. Describing diffusion phenomena in porous material the complex structure of these media has to be taken into account. As an appropriate model for the observed material structure we apply Sierpinski carpets with finite iteration depth [1] and we attempt to capture the randomness of the material by mixing Sierpinski carpet generators randomly [2,3]. Besides we consider biased diffusion of charged particles in an external field in such models. Analyzing the diffusive process we utilize different methods to determine important quantities as e.g. the random walk dimension dw. We find that this exponent dw shows a strong dependence on the mixture composition and on the structural features of the carpets analyzed.
[1] S. Tarafdar, et al., Physica A, 292, 1 (2001)
[2] D. Anh, et al., Europhys. Lett., 70, 109 (2005)
[3] D. Anh, et al., J. Phys. A: Math. Theor., 40, 11453 (2007)