Abstract
Gated heterostructures were used to determine the low-temperature behavior of the two-dimensional electron gas near filling factor in the disorder-magnetic-field plane. We identify a line on which is temperature independent, has value , and a distinct line on which . The phase boundaries between the Hall insulator and the principal quantum Hall liquids at show levitation of the delocalized states of the first Landau levels for electrons and composite fermions. Finally, the data suggest that there is no true metallic phase around .
- Received 11 September 1996
DOI:https://doi.org/10.1103/PhysRevB.54.R17323
©1996 American Physical Society