Scaling of the quantum-Hall plateau-plateau transition in graphene

Abstract

The temperature dependence of the magneto-conductivity in graphene shows that the widths of the longitudinal conductivity peaks, for the N = 1 Landau level of electrons and holes, display a power-law behavior following ∆ν ∝ T κ with a scaling exponent κ = 0.37 ± 0.05. Similarly the maximum derivative of the quantum Hall plateau transitions (dσxy/dν) max scales as T −κ with a scaling exponent κ = 0.41 ± 0.04 for both the first and second electron and hole Landau level. These results confirm the universality of a critical scaling exponent. In the zeroth Landau level, however, the width and derivative are essentially temperature independent, which we explain by a temperature independent intrinsic length that obscures the expected universal scaling behavior of the zeroth Landau level.