title: Quantum hall effect at low magnetic fields
abstract: The temperature and scale dependence of resistivities in the standard scaling theory of the integer quantum Hall effect is discussed. It is shown that recent experiments, claiming to observe a discrepancy with the global phase diagram of the quantum Hall effect, are in fact in agreement with the standard theory. The apparent low-field transition observed in the experiments is identified as a crossover due to weak localization and a strong reduction of the conductivity when Landau quantization becomes dominant.
authors.affiliation: Institut fur Theoretische Physik, Universitat zu Koln, D-50937 Koln, Germany.
authors.initials: B
authors.lastname: Huckestein