Fig. 1: Finite T phase diagram of “ideal” quantum Hall effect.
a Schematic phase diagram in the neighborhood of ν = ν⋆ (quantized filling factor) in the limit of vanishing disorder. b Resistivity tensor as a function of ν at three fixed temperatures, as indicated in panel a. At zero temperature (blue) the Hall resistivity is strictly quantized, whereas at high temperature (black) the QPWC has melted and the Hall resistivity takes its classical value. At intermediate temperatures (red), the Hall resistivity shows sharp crossovers from the classical value to the quantized one as ν moves away from ν*. Moreover, the longitudinal resistivity ρxx is very close to zero deep in the QPWC phase or near ν* but becomes finite away from those regions.
