Temperature-Abnormal Diffusivity in Tilted Periodic Potentials

Abstract

The diffusion of particles in tilted spatially periodic potentials in systems with different friction coefficients γ' has been studied in a wide temperature range. It has been shown that temperature-abnormal diffusivity is observed in a certain force interval in systems where γ' < 1.1. In the case of temperature-abnormal diffusivity, the diffusion coefficient D increases with decreasing temperature. At the same time, temperature-abnormal diffusivity is absent at large friction coefficients γ' and diffusion is always enhanced with increasing temperature. It has been analyzed how the anomalous temperature dependence of the diffusion coefficient is transformed to a normal dependence with increasing friction coefficient γ'. It has been found that a temperature-abnormal diffusivity "window" arises at certain friction coefficients. The diffusion coefficient first increases with decreasing temperature in a certain force interval and, then, decreases again. The diagrams of existence of such regions have been plotted.