Anomalous temperature dependence of diffusion in crystals in time-periodic external fields

The features of the diffusion of particles under the action of an external periodic force in a crystal lattice have been studied using computer simulation. It has been shown that the temperature dependence of the diffusion coefficients is anomalous. Diffusion can increase with a decrease in the temperature in some temperature intervals. The positions and widths of these intervals depend on the frequency of the external field. It has been found that the diffusion coefficient in the presence of a periodic external field can be more than nine orders of magnitude larger than the usual diffusion coefficient at the same temperature. The physical reasons for this anomaly have been analyzed.