Comment on "Magnetic-Field-Tuned Quantum Phase Transition in the Insulating Regime of Ultrathin Amorphous Bi Films"

TL;DR

This paper challenges previous interpretations of a quantum phase transition in disordered thin films by presenting first-principles calculations that suggest activated transport mechanisms instead.

Contribution

It offers a new theoretical explanation for experimental observations, emphasizing activated transport over quantum phase transition in disordered ultrathin films.

Findings

Activated transport explains experimental data

First-principles calculations support alternative mechanism

Challenges previous quantum phase transition interpretation

Abstract

A recent letter [Lin & Goldman, Phys. Rev. Lett. 106, 127003 (2011)] has presented experimental data in highly disordered thin films, which were interpreted as a quantum phase transition, an intriguing and surprising result for this system. Here we present a first-principles calculation which captures the observed phenomena, and provides an alternative mechanism of activated transport through the disordered landscape rather than a quantum phase transition.