Experimental Studies of Scaling Behavior of a Quantum Hall System with a Tunable Landau Level Mixing

Abstract

Temperature dependence of the longitudinal and Hall resistance is studied in the regime of localization-delocalization transition. We carry out measurements of a scaling exponent $κ$ in the Landau level mixing region at several filling factors. The localization exponent $γ$ is extracted using an approach based on the variable range hopping theory. The values of $γ$ and $κ$ are found to be universal, independent of filling factor in our sample. We can conclude that although Landau level mixing can change the degeneracy of a quantum Hall state, the value of the scaling exponent remains the same for a given sample that contains a fixed disorder profile.

11 pages, 4 figures