2001/10/21 by D. Reguera, J. M. Rubí · 2 citations
Physics and Astronomy · #cond-mat.soft #cond-mat.stat-mech
paper · pdf · doi:10.1103/physreve.64.061106
16 pages, 5 figures. Accepted for publication in Phys. Rev. E
arxiv created 2001/10/21 · arxiv updated 2016/08/15
We use the mesoscopic nonequilibrium thermodynamics theory to derive the general kinetic equation of a system in the presence of potential barriers. The result is applied to the description of the evolution of systems whose dynamics is influenced by entropic barriers. We analyze in detail the case of diffusion in a domain of irregular geometry in which the presence of the boundaries induces an entropy barrier when approaching the exact dynamics by a coarsening of the description. The corresponding kinetic equation, named Fick-Jacobs equation, is obtained, and its validity is generalized through the formulation of a scaling law for the diffusion coefficient which depends on the shape of the boundaries. The method we propose can be useful to analyze the dynamics of systems at the nanoscale where the presence of entropy barriers is a common feature.