Biased diffusion in a piecewise linear random potential
Max-Planck-Institut für Physik komplexer Systeme, Nöthnitzer Straße 38, 01187 Dresden, Germany
2 Sumy State University, 2 Rimsky-Korsakov Street, 40007 Sumy, Ukraine
Corresponding author: a email@example.com
Published online: 22 June 2010
We study the biased diffusion of particles moving in one direction under the action of a constant force in the presence of a piecewise linear random potential. Using the overdamped equation of motion, we represent the first and second moments of the particle position as inverse Laplace transforms. By applying to these transforms the ordinary and the modified Tauberian theorem, we determine the short- and long-time behavior of the mean-square displacement of particles. Our results show that while at short times the biased diffusion is always ballistic, at long times it can be either normal or anomalous. We formulate the conditions for normal and anomalous behavior and derive the laws of biased diffusion in both these cases.
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2010