Distinguishing the Two-Component Anomalous Hall Effect from the Topological Hall Effect

Area of Science:

• Condensed Matter Physics
• Spintronics
• Materials Science

Background:

• The topological Hall effect (THE) is often identified by nonmonotonic features in the Hall signal, indicative of chiral spin textures like magnetic skyrmions.
• The presence of the anomalous Hall effect (AHE) can create artifacts that mimic THE, complicating the distinction between genuine THE and two-component AHE.

Purpose of the Study:

• To confirm genuine THE coexisting with AHE.
• To develop and validate methods for distinguishing true THE from artifactual signals arising from complex AHE contributions.

Main Methods:

• Transport measurements to analyze Hall signal characteristics.
• Magneto-optical Kerr effect (MOKE) microscopy for direct visualization of magnetic textures.
• Analysis of minor hysteresis loops.
• Investigation of temperature and gate voltage dependencies.

Main Results:

• Genuine THE with AHE was confirmed and found to occur in the AHE transition region.
• Artifactual "THE" (two-component AHE) was observed beyond the saturation of the AHE component.
• Distinct behaviors in minor loops, temperature dependence, and gate dependence were identified to differentiate genuine THE from artifacts.

Conclusions:

• Genuine THE can be reliably distinguished from two-component AHE artifacts using a combination of transport, MOKE, and analysis of magnetic hysteresis, temperature, and gate dependencies.
• The proposed methods provide a robust framework for researchers to accurately identify THE in materials exhibiting complex Hall effects.