Quantum critical behaviour of the plateau-insulator transition in the quantum Hall regime

Abstract

High-field magnetotransport experiments provide an excellent tool to investigate the plateau-insulator phase transition in the integral quantum Hall effect. Here we review recent low-temperature high-field magnetotransport studies carried out on several InGaAs/InP heterostructures and an InGaAs/GaAs quantum well. We find that the longitudinal resistivity $ρ_{xx}$ near the critical filling factor $ν_{c}$ ~ 0.5 follows the universal scaling law $ρ_{xx}(ν, T) \propto exp[-Δν/(T/T_{0})^κ]$, where $Δν=ν-ν_{c}$. The critical exponent $κ$ equals $0.56 \pm 0.02$, which indicates that the plateau-insulator transition falls in a non-Fermi liquid universality class.

8 pages, accepted for publication in Proceedings of the Yamada Conference LX on Research in High Magnetic Fields (August 16-19, 2006, Sendai)