Colossal anomalous Hall effect in the layered antiferromagnetic EuAl₂Si₂ compound

Area of Science:

• Condensed Matter Physics
• Materials Science
• Magnetism

Background:

• The anomalous Hall effect (AHE) is crucial in spintronics, with extrinsic mechanisms offering higher Hall responses than intrinsic Berry curvature.
• Achieving large anomalous Hall conductivity and angle simultaneously is challenging due to high conductivity and weak skew scattering in clean systems.

Purpose of the Study:

• To explore new magnetic metal systems for enhanced extrinsic anomalous Hall effect.
• To investigate the mechanisms behind colossal anomalous Hall response in novel materials.

Main Methods:

• Experimental characterization of the magnetic metal EuAl2Si2.
• Analysis of the anomalous Hall effect, conductivity, and Hall angle.
• Investigating scaling relations to determine dominant scattering mechanisms.

Main Results:

• EuAl2Si2 exhibits colossal anomalous Hall conductivity (σAxy ≥ 10^4 Ω⁻¹ cm⁻¹) and a large anomalous Hall angle (AHA >10%).
• Scaling relations indicate the skew scattering mechanism is dominant, leading to a large skew scattering constant.
• The observed anomaly is attributed to large spin-orbit coupling (SOC) and a large magnetic moment.

Conclusions:

• EuAl2Si2 is a promising material for studying extrinsic AHE mechanisms.
• The material demonstrates a new platform for achieving significant AHE responses.
• The findings advance the understanding of extrinsic AHE contributions in magnetic materials.