Kimata Motoi, Sasabe Norimasa, Kurita Kensuke, Yamasaki Yuichi, Tabata Chihiro, Yokoyama Yuichi, Kotani Yoshinori, Ikhlas Muhammad, Tomita Takahiro, Amemiya Kenta, Nojiri Hiroyuki, Nakatsuji Satoru, Koretsune Takashi, Nakao Hironori, Arima Taka-Hisa, Nakamura Tetsuya
Institute for Materials Research, Tohoku University, Sendai, Miyagi, 980-8577, Japan.
Japan Synchrotron Radiation Research Institute (JASRI), 1-1-1 Kouto, Sayo, Hyogo, 679-5198, Japan.
Nat Commun. 2021 Sep 22;12(1):5582. doi: 10.1038/s41467-021-25834-7.
Recently found anomalous Hall, Nernst, magnetooptical Kerr, and spin Hall effects in the antiferromagnets MnX (X = Sn, Ge) are attracting much attention for spintronics and energy harvesting. Since these materials are antiferromagnets, the origin of these functionalities is expected to be different from that of conventional ferromagnets. Here, we report the observation of ferroic order of magnetic octupole in MnSn by X-ray magnetic circular dichroism, which is only predicted theoretically so far. The observed signals are clearly decoupled with the behaviors of uniform magnetization, indicating that the present X-ray magnetic circular dichroism is not arising from the conventional magnetization. We have found that the appearance of this anomalous signal coincides with the time reversal symmetry broken cluster magnetic octupole order. Our study demonstrates that the exotic material functionalities are closely related to the multipole order, which can produce unconventional cross correlation functionalities.
最近在反铁磁体MnX（X = Sn，Ge）中发现的反常霍尔效应、能斯特效应、磁光克尔效应和自旋霍尔效应，在自旋电子学和能量收集方面引起了广泛关注。由于这些材料是反铁磁体，这些功能的起源预计与传统铁磁体不同。在此，我们通过X射线磁圆二色性报告了MnSn中磁八极子的铁性有序的观测结果，到目前为止这仅在理论上有预测。观测到的信号与均匀磁化行为明显解耦，表明当前的X射线磁圆二色性并非源于传统磁化。我们发现这种反常信号的出现与时间反演对称性破缺的团簇磁八极子有序相一致。我们的研究表明，奇异的材料功能与多极有序密切相关，多极有序可以产生非常规的交叉关联功能。
