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

TL;DR

This study investigates the quantum Hall plateau-insulator transition through low-temperature magnetotransport experiments, revealing universal scaling behavior and a critical exponent indicating a non-Fermi liquid universality class.

Contribution

The paper provides experimental evidence of universal scaling laws and critical exponents for the plateau-insulator transition in quantum Hall systems, highlighting non-Fermi liquid behavior.

Findings

Resistivity near critical point follows universal exponential scaling

Critical exponent κ measured as 0.56 ± 0.02

Transition belongs to a non-Fermi liquid universality class

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 $\rho_{xx}$ near the critical filling factor $\nu_{c}$ ~ 0.5 follows the universal scaling law $\rho_{xx}(\nu, T) \propto exp[-\Delta \nu/(T/T_{0})^{\kappa}]$, where $\Delta \nu =\nu -\nu_{c}$. The critical exponent $\kappa$ equals $0.56 \pm 0.02$, which indicates that the plateau-insulator transition falls in a non-Fermi liquid universality class.