Anti-Levitation in the Integer Quantum Hall Systems

Abstract

Two-dimensional electron gas in the integer quantum Hall regime is investigated numerically by studying the dynamics of an electron hopping on a square lattice subject to a perpendicular magnetic field and random on-site energy with white noise distribution. Focusing on the lowest Landau band we establish an anti-levitation scenario of the extended states: As either the disorder strength $W$ increases or the magnetic field strength $B$ decreases, the energies of the extended states move below the Landau energies pertaining to a clean system. Moreover, for strong enough disorder, there is a disorder dependent critical magnetic field $B_c(W)$ below which there are no extended states at all. A general phase diagram in the $W-1/B$ plane is suggested with a line separating domains of localized and delocalized states.

8 pages, 9 figures

References in corpus (2)

• Critical exponent for the quantum Hall transition
• Levitation and percolation in quantum Hall systems with correlated disorder

Cited by in corpus (4)

• Anderson Localization and Quantum Hall Effect: Numerical Observation of Two Parameter Scaling
• Integer Quantum Hall Effect: Disorder, temperature, floating, and plateau width
• Observation of anti-levitation of Landau levels in vanishing magnetic fields
• Effects of dilution in a 2D topological magnon insulator