Probing the plateau-insulator quantum phase transition in the quantum Hall regime

Abstract

We report quantum Hall experiments on the plateau-insulator transition in a low mobility In_{.53} Ga_{.47} As/InP heterostructure. The data for the longitudinal resistance ρ_{xx} follow an exponential law and we extract a critical exponent κ= .55 \pm .05 which is slightly different from the established value κ= .42 \pm .04 for the plateau transitions. Upon correction for inhomogeneity effects, which cause the critical conductance σ_{xx}^* to depend marginally on temperature, our data indicate that the plateau-plateau and plateau- insulator transitions are in the same universality class.