Metal-Insulator Transition Tuned by External Gates in Hall Systems with Constrictions

TL;DR

This paper investigates how external gates induce a metal-insulator transition in quantum Hall systems with constrictions, explaining it through edge state splitting into conducting and insulating regions.

Contribution

It provides a theoretical explanation for gate-tuned metal-insulator transitions in quantum Hall systems, emphasizing edge state splitting and stability against impurity scattering.

Findings

Edge splitting into conducting and insulating stripes occurs.

Impurity scattering does not destabilize the edge structure.

The transition can be controlled by external gating.

Abstract

The nature of a metal-insulator transition tuned by external gates in quantum Hall (QH) systems with point constrictions, as reported in recent experiments of Roddaro et al [1], is examined. We attribute this phenomenon to a splitting of the integer edge into conducting and insulating stripes, the latter wide enough to allow for the stability of the edge structure. Inter-channel impurity scattering and inter-channel Coulomb interactions do not destabilize this picture.