Quantum Hall Effect induced by electron-electron interaction in disordered GaAs layers with 3D spectrum

TL;DR

This paper demonstrates that the Quantum Hall Effect observed in heavily doped GaAs layers with a three-dimensional spectrum is induced by electron-electron interactions, revealing universal temperature-dependent conductance features.

Contribution

It shows that electron-electron interactions can induce the Quantum Hall Effect in disordered 3D GaAs layers, a novel mechanism compared to traditional explanations.

Findings

Quantum Hall Effect observed in 3D GaAs layers with mean free path shorter than thickness.

Universal logarithmic temperature dependence of conductance minima.

Presence of a wide Hall resistance plateau at low activation energy.

Abstract

It is shown that the observed Quantum Hall Effect in epitaxial layers of heavily doped n-type GaAs with thickness (50-140 nm) larger the mean free path of the conduction electrons (15-30 nm) and, therefore, with a three-dimensional single-particle spectrum is induced by the electron-electron interaction. The Hall resistance R_xy of the thinnest sample reveals a wide plateau at small activation energy E_a=0.4 K found in the temperature dependence of the transverse resistance R_xx. The different minima in the transverse conductance G_xx of the different samples show a universal temperature dependence (logarithmic in a large range of rescaled temperatures T/T_0) which is reminiscent of electron-electron-interaction effects in coherent diffusive transport.