Weak localization correction to the anomalous Hall effect in polycrystalline Fe films

TL;DR

This study investigates how weak localization effects influence the anomalous Hall effect in ultrathin polycrystalline Fe films, revealing a universal correction at low disorder and deviations at higher disorder due to granularity.

Contribution

First demonstration of a universal weak localization correction to the anomalous Hall conductivity in ultrathin Fe films within the skew scattering model.

Findings

Logarithmic temperature dependence of $\sigma_{xy}$ for low resistance

Universal scale-dependent correction observed at low disorder

Breakdown of universality at higher disorder due to granularity

Abstract

In situ transport measurements have been made on ultrathin ($<$100 {\AA} thick) polycrystalline Fe films as a function of temperature and magnetic field for a wide range of disorder strengths. For sheet resistances $R_{xx}$ less than $\sim 3k\Omega$, we find a logarithmic temperature dependence of the anomalous Hall conductivity $\sigma_{xy}$ which is shown for the first time to be due to a universal scale dependent weak localization correction within the skew scattering model. For higher sheet resistance, granularity becomes important and the break down of universal behavior becomes manifest as the prefactors to $\sigma_{xx}$ and $\sigma_{xy}$ decrease at different rates with increasing disorder.