ANOMALOUS ELECTRIC-FIELD-INDUCED LOCALIZATION IN QUASI-PERIODIC SYSTEMS

We study the localization of the electronic wave functions of quasiper iodic superlattices in an electric field. Although the electric field localizes the states on average, an exotic behavior appears at certain values of the electric field applied, for which the localization leng th of the states presents local maxima, and the states become more ext ended. We explain this effect by considering that the field limits the region of the system reachable by the electron. (C) 1997 Elsevier Sci ence B.V.