Electrical nucleation, displacement, and detection of antiferromagnetic domain walls in the chiral antiferromagnet Mn3Sn

Antiferromagnetic systems for application in spintronics are less developed that their ferromagnetic counterparts but offer the prospect of increased stability and speed in their magnetisation dynamics. Here, the authors investigate the electrical detection and displacement of antiferromagnetic domain walls in Mn3Sn single crystals. Antiferromagnets exhibiting distinctive responses to the electric and magnetic fields have attracted attention as breakthrough materials in spintronics. The current-induced Neel-order spin-orbit torque can manipulate the antiferromagnetic domain wall (AFDW) in a collinear CuMnAs owing to a lack of local inversion symmetry. Here, we demonstrate that the electrical nucleation, displacement, and detection of AFDWs are also possible in a noncollinear antiferromagnet, i.e., chiral Mn3Sn with local inversion symmetry. The asymmetric magnetoresistance measurements reveal that AFDWs align parallel to the kagome planes in the microfabricated wire. Numerical calculation shows these AFDWs consist of stepwise sub-micron size Bloch wall-like spin textures in which the octupole moment gradually rotates over three segments of domain walls. We further observed that the application of a pulse-current drives these octupole based AFDWs along the wire. Our findings could provide a guiding principle for engineering the AFDW structure in the chiral antiferromagnetic materials.