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. 
Richard Berkovits, Jan W. Kantelhardt, Yshai Avishai, Shlomo Havlin,   Armin Bunde