Cross-over between Magnetic and Electric Edges in Quantum Hall Systems

TL;DR

This paper investigates the transition from magnetic to electric edge transport in a quantum Hall system, demonstrating how magnetic and electric edge states compete and transition under tunable conditions, with theoretical modeling aligning with experimental results.

Contribution

It introduces a novel experimental setup to control and observe the crossover between magnetic and electric edge conduction in quantum Hall systems, supported by a quantum Boltzmann equation model.

Findings

Magnetic edge conduction competes with electric edge conduction.

Transition occurs as magnetic edges become depleted.

Model accurately predicts the bulk-edge crossover.

Abstract

We report on the transition from magnetic edge to electric edge transport in a split magnetic gate device which applies a notch magnetic field to a two-dimensional electron gas. The gate bias allows tuning the overlap of magnetic and electric edge wavefunctions on the scale of the magnetic length. Conduction at magnetic edges - in the 2D-bulk - is found to compete with conduction at electric edges until magnetic edges become depleted. Current lines then move to the electrostatic edges as in the conventional quantum Hall picture. The conductivity was modelled using the quantum Boltzmann equation in the exact hybrid potential. The theory predicts the features of the bulk-edge cross-over in good agreement with experiment.