Anomalous Hall resistance in Ge:Mn systems with low Mn concentrations

TL;DR

This paper investigates the anomalous Hall effect in low Mn concentration Ge:Mn systems, demonstrating that a two-band conduction model explains the observed Hall resistance features.

Contribution

It introduces a two-band conduction explanation for the anomalous Hall effect in Ge:Mn with very low Mn concentrations, expanding understanding of ferromagnetic semiconductors.

Findings

AHE observed at Mn concentrations as low as 0.004%.

Hall resistance features explained by two-band conduction model.

No hysteresis observed in the Hall effect.

Abstract

Taking Mn doped Germanium as an example, we evoke the consideration of a two-band-like conduction in diluted ferromagnetic semiconductor (FMS). The main argument for claiming Ge:Mn as a FMS is the occurrence of the anomalous Hall effect (AHE). Usually, the reported AHE (1) is observable at temperatures above 10 K, (2) exhibits no hysteresis, and (3) changes the sign of slope. We observed a similar Hall resistance in Mn implanted Ge with the Mn concentration as low as 0.004%. We show that the puzzling AHE features can be explained by considering a two-band-like conduction in Ge:Mn.