Interaction footprints in two-dimensional disordered electronic systems

The effect of electron—electron interaction on the properties of a two-dimensional disordered electronic system are studied, guided by the quest for a cojectured existence of a possibly interaction induced metal-insulator transition (MIT). Numerical simulations performed on small systems indicate that the long-range Coulomb electron-electron interaction leads to a significant enhancement of the persistent current. At the same time, the effect of electron-electron interaction on the conductance is rather small so that, strictly speaking, there is no interaction-induced MIT in two-dimensional electronic systems. Finally, the statistics of energy levels for strongly correlated disordered systems is discussed, and the variation in statistics as a function of the electron-electron interaction is traced.