The effect of inter-Landau-band mixing on extended states in quantum Hall system

Gang Xiong, Shi-Dong Wang, Qian Niu, Yupeng Wang, X. C. Xie, De-Cheng Tian, X. R. Wang

Published 2003-05-01Version 1

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 {\it 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 {\it 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 {\it consistent} with our theory.