Destruction of Integer Quantum Hall Effect at Strong Disorder: A Numerical Study

D. N. Sheng；Z. Y. Weng；Q. Gao

Chinese Journal of Physics

36卷2S期（1998 / 04 / 01）

433 - 439

英文

A breakdown of integer quantum Hall effect (IQHE) at strong disorder is studied numerically in a lattice model. We find a generic sequence by which the integer quantum Hall plateaus disappear: higher IQHE plateaus always vanish earlier than lower ones. We show that extended levels between these plateaus do not float up in energy but keep merging together after the disappearance of plateaus, which eventually leads to a localization in the whole system. We also study this phenomenon in terms of topological property, which provides a simple physical explanation.