Influence of correlated disorder potentials on the levitation of current carrying states in the quantum Hall effect

The disorder driven quantum Hall to insulator transition is investigated for a two-dimensional lattice system. We consider a Gaussian correlated random potential, study the behaviour of the current carrying states and trace their energetical position when the disorder strength is increased. Our results qualitatively resemble those obtained previously for exponentially correlated disorder potentials. We find both the downward movement of the anti-Chern states as well as the floating up of the Chern states across the Landau gap which is sometimes masked by the global broadening of the tight binding band.