2026-06-19 東北大学
図1 らせん磁性体の巻き方制御。原子が持つ磁気モーメントがらせん状に整列しており、 右巻き・左巻きの巻き方の自由度が生じる。電流と磁場を同時に印加すると左巻きまたは右巻きに揃えることができる。らせん磁性メモリではこれらを”0″と”1″に割り当てる。
＜関連情報＞
- https://www.tohoku.ac.jp/japanese/2026/06/press20260619-01-helimagnetic.html
- https://www.pnas.org/doi/10.1073/pnas.2600410123
スピン偏極中性子散乱によるヘリ磁性YMn6Sn6における電気的キラリティ制御の直接実証 Direct demonstration of electric chirality control in a helimagnetic YMn6Sn6 by spin-polarized neutron scattering
Hidetoshi Masuda, Yutaro Yanagisawa, Kazuki Ohishi, +2 , and Yoshinori Onose
Proceedings of the National Academy of Sciences Published:June 16, 2026
DOI:https://doi.org/10.1073/pnas.2600410123
Significance
Chirality, the breaking of mirror symmetry in materials, can encode information by controlling the right- and left-handed states. Magnetic chirality in helimagnets, free from crystal and device structures, offers a promising platform for such spintronic applications. Recent studies have indeed suggested electric current chirality control in metallic helimagnets; however, this was only inferred by indirect electronic measurements. In this study, we demonstrate effective and deterministic chirality control over the entire sample volume by utilizing spin-polarized neutron diffraction, which is capable of directly probing magnetic chirality. This result provides a concrete cornerstone for the emerging field of spintronics based on helimagnetic chirality.
Abstract
The spiral handedness of magnetic moments, referred to as chirality, gives rise to emergent electromagnetic phenomena in helimagnets. In insulating helimagnets, known as multiferroics, the cycloidal spin structure induces electric polarization by utilizing the inverse Dzyaloshinskii–Moriya mechanism. Spin-polarized neutron diffraction experiments, which directly probe circular spin arrangements, clearly demonstrated that an electric field controlled the chirality in multiferroic helimagnets. On the other hand, it was unclear until recently how the chirality could be controlled in metallic helimagnets where a large electric field cannot be applied, while the chirality control technique in metallic helimagnets should enable the exploration of chirality-dependent spintronic functionalities. Recently, Jiang et al. succeeded in controlling the chirality of a spiral structure by the simultaneous application of a magnetic field and electric current in a metallic helimagnet, utilizing the nonreciprocal electronic transport as an indirect probe of chirality, highlighting the need for a neutron diffraction experiment that directly probes the chirality. Here, we directly demonstrate the chirality control in a metallic helimagnet YMn6Sn6 by means of spin-polarized neutron diffraction, which should give rise to a firm basis for the development of future helimagnetic spintronics.
