No indications of metal-insulator transition for systems of interacting electrons in two dimensions

The influence of Coulomb interaction on transport properties of spinless electrons in small disordered two-dimensional systems is studied within a tight-binding model. Spatial correlations, inverse participation ratio, and multifractal spectrum of the zero-temperature local tunneling amplitude as well as the dc Kubo conductance are traced as function of the interaction strength U. When U is increased, all of the above quantities are shifted rather smoothly towards localized behavior, indicating the absence of an interaction-driven insulator-metal transition.