ACCELERATION OF DIFFUSION IN SUBCRITICALLY TILTED PERIODIC POTENTIALS

We study the enhancement of effective diffusion coefficient of an overdamped Brownian particle in tilted periodical potential profile. For analysis we use the model piece-wise linear potential, where independent variation of the potential profile parameters (such as height and width of potential barriers, width of potential wells and period of potential profile) is possible. This approach allows to investigate the influence of potential profile shape on the conditions for the diffusion acceleration, maximal value of the diffusion coefficient, values of noise intensity and the tilt for which the maximum occurs. For the large barriers and subcritical tilt the results are generalized for arbitrary shape of potential profile.