Comment on ``Topological Oscillations of the Magnetoconductance in Disordered GaAs Layers''

TL;DR

This paper critiques a recent study on magnetoconductance oscillations in disordered GaAs layers, emphasizing the importance of correct scaling ideas in quantum transport theory.

Contribution

It clarifies misconceptions in Murzin et al.'s interpretation of topological effects and scaling in quantum Hall systems.

Findings

Highlights the importance of proper scaling in quantum transport

Critiques the interpretation of instanton effects in magnetoresistance

Emphasizes the development of accurate microscopic theories

Abstract

In a recent Letter, Murzin et. al. [Phys. Rev. Lett., vol. 92, 016802 (2004)] investigated "instanton effects" in the magneto resistance data taken from samples with heavily Si-doped GaAs layers at low temperatures. This topological issue originally arose in the development of a microscopic theory of quantum Hall effect some 20 years ago. The investigations by Murzin et. al., however, do not convey the correct ideas on scaling that have emerged over the years in the general theory of quantum transport.