Dynamic localization with an impurity under the action of an AC electric field

We have investigated the motion of a charged particle in a one-dimensional system with an impurity under the action of AC electric field. We find that initially localized electron will remain localized if the ratio of the AC field magnitude and the frequency is a root of the ordinary zero-order Bessel function and the localization effect depends on the ratio epsilon(0)/omega, where epsilon(0) is the impurity potential and omega is the AC-field frequency. In contrast to the case of no impurity, no matter what the value eaE/omega is, the particle is localized when the impurity potential is sufficiently strong. (C) 2000 Elsevier Science B.V. All rights reserved.