Two Interacting Electrons in a Disorder Potential: Localization Properties

Two electrons move in a quasi one--dimensional wire under the influence of a short--range interaction. We restrict Hilbert space to those states where the two electrons are close to each other. Using supersymmetry, we present a complete analytical solution to this problem. The two--body interaction affects the density of states and, thereby, the localization length. We derive a criterion for the onset of changes of the localization length due to the two--body interaction.