Experimental observation of topological Hall effects in compensated ferrimagnet-heavy metal layered structures

The topological Hall effect (THE) as a powerful probe for the experimental observation of topological spin textures, such as magnetic skyrmions, has been observed in a wide variety of distinct material systems. However, limited experimental observations have been reported for antiferromagnetic (AFM) materials. Here, the THE signals in the AFM state were observed in compensated ferrimagnetic thin films interfaced with heavy metals at the magnetization compensation temperature (T-M). Ferrimagnetic CoTb thin films grown on Pt thin films were used in the experiments. The CoTb films exhibited a magnetization compensation point at which the moments of Co and Tb sublattices canceled each other, giving rise to the AFM state. The temperature (T)-dependent Hall measurements showed anomalous Hall effect (AHE) and THE responses at T not equal T-M but pure THE responses at T = T-M. Control measurements and analyses suggest that the THE responses are associated with interfacial Dzyaloshinskii-Moriya interaction (DMI) rather than the overlapping of different AHE signals in the structure. This work presents the first-ever observation of interfacial DMI-induced THE in AFM metal trilayered systems and demonstrates a new approach for electrical reading of chiral spin textures in AFM thin film-based heterostructures.

Automated summary

This study presents the first-ever observation of interfacial DMI-induced THE in AFM metal trilayered systems, and demonstrates a new approach for electrical reading of chiral spin textures in AFM thin film-based heterostructures.