Possible existence of a band of extended states induced by   inter-Landau-band mixing in quantum Hall system
  The mixing of states with {\it opposite chirality} in quantum Hall system is shown to have delocalization effect. It is possible that extended states may form bands because of this mixing, as is shown through a numerical calculation on a two-channel network model. Based on this result, a new phase diagram with a narrow {\it metallic} phase separating two adjacent QH phases and/or separating a QH phase from the insulating phase is proposed. The data from recent non-scaling experiments is reanalyzed and shown that they seem to be {\it consistent} with the new phase diagram. However, due to finite-size effects, further study on large system size is still needed to conclude whether there are extended state bands in thermodynamic limit. 
Gang Xiong, Shi-Dong Wang, Qian Niu, Yupeng Wang, X. C. Xie, De-Cheng   Tian, X. R. Wang