Observation of Cluster Magnetic Octupole Domains in the Antiferromagnetic Weyl Semimetal Mn3Sn Nanowire

The antiferromagnetic Weyl semimetal Mn₃Sn has attracted wide attention due to its vast anomalous transverse transport properties despite barely any net magnetization. So far, the magnetic properties of Mn₃Sn have been experimentally investigated on micrometer scale samples but not in nanometers. In this study, we measured the local anomalous Nernst effect of a (0001)-textured Mn₃Sn nanowire using a tip-contact-induced temperature gradient with an atomic force microscope. Our approach directly maps the distribution of the cluster magnetic octupole moments with 80 nm spatial resolution, providing crucial information for integrating the Mn₃Sn nanostructure into spintronic devices.