LOCALIZATION PROPERTIES OF ONE-DIMENSIONAL RANDOM ELECTRIFIED CHAINS

A Kronig-Penney model with a constant electric held F for a non-intera cting electron is used to study the transmission properties of the And erson transition in one-dimensional systems with disordered delta-func tion potentials. We examine the cases where the potential varies unifo rmly from 0 to W (barriers) or from -W to 0 (wells) for a given disord er W. We observe jumps in the transmission coefficient at the points E + Fx = pi(2) pi(2) (where E is the electron energy and n an integer). These jumps are related to the small oscillations observed by Soukoul is et al in the mixed case (potentials from -W/2 to W/2). However, an interesting feature is found in the wells in the range between two jum ps. It is observed that in the presence of a small field the states be come more localized and the localization length decreases up to a mini mum for a critical value F-m instead of increasing. Finally, we have s tudied the effect of the disorder on the Anderson transition by means of the participation ratio and the localization length.