Scaling of the quantum Hall plateau-plateau transition in graphene

We show that the width of the longitudinal magnetoconductivity peaks in graphene related to the N=1 Landau level displays a power-law type temperature dependence, Δν Tκ, with κ=0.37±0.05. Similarly, the derivative of the Hall conductivity at the plateau transition, (d σxy /dν), scales as T-κ with κ=0.41±0.04 for both the first and second Landau levels of electrons and holes. These results confirm the universality of a critical quantum Hall scaling in the higher Landau levels of graphene. In the zeroth Landau level, however, Δν and d σxy /dν are essentially temperature independent, pointing toward a different type of scaling that is possibly governed by a temperature independent intrinsic length. © 2009 The American Physical Society.