Zakeri Khalil, von Faber Albrecht, Mankovsky Sergiy, Ebert Hubert
Heisenberg Spin-dynamics Group, Physikalisches Institut, Karlsruhe Institute of Technology, Wolfgang-Gaede-Strasse 1, D-76131, Karlsruhe, Germany.
Department of Chemistry and Physical Chemistry, LMU Munich, Butenandtstrasse 11, D-81377, Munich, Germany.
Adv Mater. 2025 Sep;37(35):e2500152. doi: 10.1002/adma.202500152. Epub 2025 Jul 1.
Chirality is one of the inherent characteristics of some objects in nature. In magnetism, chiral magnetic textures can be formed in systems with broken inversion symmetry and due to an antisymmetric magnetic interaction, known as Dzyaloshinskii-Moriya interaction (DMI). Here, aiming for a fundamental understanding of this chiral interaction on the atomic scale, several synthetic layered structures composed of alternating atomic layers of 3d ferromagnetic metals epitaxially grown on the Ir(001) surface are designed. It is demonstrated both experimentally and theoretically that the atomistic DMI depends critically not only on the orbital occupancy of the interface magnetic layer but also on the sequence of the atomic layers. It is shown that even large atomistic DMI values can result in a small effective DMI, and conversely. Furthermore, the dependence of the effective DMI on the number of atomic layers deviates from a simple scaling law. These observations are attributed to the complexity of the electronic structure and the contributions of different orbitals to the hybridization and DMI. The results are anticipated to provide guidelines for achieving full control over both the chirality and the magnitude of the atomistic DMI in layered materials.
手性是自然界中某些物体的固有特性之一。在磁性领域，在手性磁织构可在具有反演对称性破缺的系统中形成，这是由于一种反铁磁相互作用，即所谓的Dzyaloshinskii-Moriya相互作用（DMI）。在此，为了从原子尺度上对这种手性相互作用有一个基本的理解，设计了几种由3d铁磁金属的交替原子层在Ir(001)表面外延生长而成的合成层状结构。实验和理论均表明，原子尺度的DMI不仅关键地取决于界面磁层的轨道占据情况，还取决于原子层的顺序。结果表明，即使大的原子尺度DMI值也可能导致小的有效DMI，反之亦然。此外，有效DMI对原子层数的依赖性偏离了简单的标度律。这些观察结果归因于电子结构的复杂性以及不同轨道对杂化和DMI的贡献。预期这些结果将为在层状材料中实现对手性和原子尺度DMI大小的完全控制提供指导。
