Anomalous Hall effect in field-effect structures of (Ga,Mn)As

TL;DR

This study investigates the anomalous Hall effect in (Ga,Mn)As structures, revealing unexpected temperature-dependent behavior and a scaling relation between conductances, influenced by disorder and carrier density.

Contribution

It provides new insights into the temperature dependence and scaling behavior of the anomalous Hall effect in thin (Ga,Mn)As layers with varying disorder and carrier densities.

Findings

Unanticipated temperature dependence of $\sigma_{xy}$, including sign change.

Scaling relation between $\sigma_{xy}$ and $\sigma_{xx}$ in disordered channels.

High Curie temperature samples show distinct Hall conductance behavior.

Abstract

The anomalous Hall effect in metal-insulator-semiconductor structures having thin (Ga,Mn)As layers as a channel has been studied in a wide range of Mn and hole densities changed by the gate electric field. Strong and unanticipated temperature dependence, including a change of sign, of the anomalous Hall conductance $\sigma_{xy}$ has been found in samples with the highest Curie temperatures. For more disordered channels, the scaling relation between $\sigma_{xy}$ and $\sigma_{xx}$, similar to the one observed previously for thicker samples, is recovered.