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

Y. J. Zhao, T. Tu, X. J. Hao, G. C. Guo, H. W. Jiang, G. P. Guo

Published 2008-07-02Version 1

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 $\kappa$ in the Landau level mixing region at several filling factors. The localization exponent $\gamma$ is extracted using an approach based on the variable range hopping theory. The values of $\gamma$ and $\kappa$ 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.