A Tunable Anomalous Hall Effect in a Non-Ferromagnetic System

TL;DR

This paper reports on the observation of a tunable anomalous Hall effect in a non-ferromagnetic, magnetically-doped 2D electron system, linked to paramagnetic polarization and skew-scattering mechanisms.

Contribution

It demonstrates a controllable anomalous Hall effect in a non-ferromagnetic system, connecting it to paramagnetic behavior and scattering processes.

Findings

Excess Hall resistivity increases as temperature decreases.

The excess Hall resistivity correlates with paramagnetic polarization.

Skew-scattering near localization crossover explains the observations.

Abstract

We measure the low-field Hall resistivity of a magnetically-doped two-dimensional electron gas as a function of temperature and electrically-gated carrier density. Comparing these results with the carrier density extracted from Shubnikov-de Haas oscillations reveals an excess Hall resistivity that increases with decreasing temperature. This excess Hall resistivity qualitatively tracks the paramagnetic polarization of the sample, in analogy to the ferromagnetic anomalous Hall effect. The data are consistent with skew-scattering of carriers by disorder near the crossover to localization.