Spin chirality in antiferromagnets offers new opportunities for spintronics. The kagome antiferromagnet Mn3Sn is a paradigmatic material in which the antiferromagnetic order parameter can be detected and controlled by electrical means. However, direct investigation of the magnetic texture of Mn3Sn has been challenging because of the tiny moment hosted in its magnetic octupole, hindering further clarification of this unique material. Here, we address this issue by observing the stray magnetic field from Mn3Sn using a diamond quantum scanning magnetometer. The spatially-resolved intrinsic domains and domain walls in a high-quality single-crystalline Mn3Sn film quantitatively reveal the polarization angle of the magnetic octupole in the kagome plane, the domain's local magnetization, the domain wall's width and chirality, and the octupole order in domain walls. Our nanoscale investigation of Mn3Sn, a powerful complement to macroscopic measurements, paves the road for developing chiral antiferromagnetism and its potential for spintronic applications.
@article{arxiv.2410.23607,
title = {Observation of chiral domain walls in an octupole-ordered antiferromagnet},
author = {Moeta Tsukamoto and Zhewen Xu and Tomoya Higo and Kouta Kondou and Kento Sasaki and Mihiro Asakura and Shoya Sakamoto and Pietro Gambardella and Shinji Miwa and YoshiChika Otani and Satoru Nakatsuji and Christian L. Degen and Kensuke Kobayashi},
journal= {arXiv preprint arXiv:2410.23607},
year = {2024}
}