The effect of inter-Landau-band mixing on extended states in quantum Hall system
The effect of inter-Landau-band mixing on electron localization in an integer quantum Hall system is studied. We find that mixing of localized states with opposite chirality tends to delocalize the states. This delocalization effect survives the quantum treatment. Extended states form bands because of this mixing, as we show through a numerical calculation on a two-channel network model. Based on this result, we propose a new phase diagram with a narrow metallic phase that separates any neighboring QH phases from each other and also separates each of them from the insulating phase. We reanalyzed the data from recent non-scaling experiments, and show that they are consistent with our theory.