Broadening processes in GaAs delta-doped quantum wire superlattices

TL;DR

This study investigates the broadening of Landau levels in GaAs delta-doped quantum wire superlattices using high magnetic field experiments, providing insights into the origins of broadening and its relation to localization effects.

Contribution

It introduces a general resistivity formula for the Quantum Hall effect that incorporates a dephasing factor linked to localization processes.

Findings

Identified the origin of Landau level broadening from experimental damping factors.

Developed a theoretical formula connecting resistivity and localization.

Analyzed broadening mechanisms in both 2D and 1D superlattices.

Abstract

We use both Quantum Hall and Shubnikov de Haas experiments at high magnetic field and low temperature to analyse broadening processes of Landau levels in a delta-doped 2D quantum well superlattice and a 1D quantum wire superlattice generated from the first one by controlled dislocation slips. We deduce first the origin of the broadening from the damping factor in the Shubnikov de Haas curves in various configurations of the magnetic field and the measured current for both kinds of superlattice. Then, we write a general formula for the resistivity in the Quantum Hall effect introducing a dephasing factor we link to the process of localization.