2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/16128The fate of integer quantum Hall effect (IQHE) at weak magnetic field is studied numerically in the presence of {\it correlated} disorders. We find a systematic {\it float-up} and {\it merging} picture for extended levels on the low-energy side which results in direct transitions from higher-plateau IQHE states to the insulator. Such direct transitions are controlled by a quantum critical point with a {\it universal} scaling form of conductance. The phase diagram is in good agreement with recent experiments. The issue of continuum vs. lattice model is also discussed.4 pages, 4 figuresMesoscale and Nanoscale Physicstext