Challenges in identifying chiral spin textures via the topological Hall effect

Chiral spin textures such as skyrmions are of interest to the field of spintronics for their potential use in future computing devices. Hall effect measurements are a simple and powerful method to probe the electronic and magnetic properties of materials. The topological Hall effect, which appears as anomalies in Hall resistance versus magnetic field measurements compared to magnetic measurements, has frequently been used to establish the occurrence of chiral spin textures. However, in addition to experimental issues, intrinsic electronic mechanisms combined with inhomogeneity in materials and at interfaces can lead to an inhomogeneous anomalous Hall effect which could be mistaken for a topological Hall signal. This review covers recent research using Hall effect measurements to probe chiral spin textures, focusing on SrRuO₃ as a model system. The ambiguity between Hall effects due to topological sources has led to disagreement in the interpretation of experimental results and casts doubts on the effectiveness of these techniques for investigating chiral spin textures.