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 In0.53Ga0.47As/InP heterostructure. The data for the longitudinal resistance ρxx follow an exponential law and we extract a critical exponent κ = 0.55±0.05 which is slightly different from the established value κ = 0.42±0.04 for the plateau transitions. Upon correction for inhomogeneity effects, which cause the critical conductance σxx* to depend marginally on temperature, our data indicate that the plateau-plateau and plateau-insulator transitions are in the same universality class. © 2000 The American Physical Society.