Insulator, semiclassical oscillations and quantum Hall liquids at low   magnetic fields
  Magneto-transport measurements are performed on two-dimensional GaAs electron systems to probe the quantum Hall (QH) effect at low magnetic fields. Oscillations following the Shubnikov-de Haas (SdH) formula are observed in the transition from the insulator to QH liquid when the observed almost temperature-independent Hall slope indicates insignificant interaction correction. Our study shows that the existence of SdH oscillations in such a transition can be understood based on the non-interacting model. 
Shun-Tsung Lo, Yi-Ting Wang, G Bohra, E Comfort, T-Y Lin, M-G Kang, G   Strasser, J P Bird, C F Huang, Li-Hung Lin, J C Chen...
cond-mat.mes-hall cond-mat.str-el