2次元磁石のツイスト工学における新しい視点 A new perspective in twist engineering of 2D magnets
2023-09-11 韓国基礎科学研究院(IBS)
◆磁気構造の変化に伴い、トポロジカル磁気バンドが現れ、それぞれ異なるトポロジカルエッジモードを持つことが示されました。この発見は、マグノンバンドトポロジーの理解を深め、トポロジカルエッジモードの制御可能性を提供し、基礎物理学から材料科学と工学に至る革新的な研究を可能にします。
＜関連情報＞
- https://www.ibs.re.kr/cop/bbs/BBSMSTR_000000000738/selectBoardArticle.do
- https://pubs.acs.org/doi/10.1021/acs.nanolett.3c01529
ツイスト二層CrI3における初期スピンハミルトニアンとトポロジカル非対称磁性 Ab Initio Spin Hamiltonian and Topological Noncentrosymmetric Magnetism in Twisted Bilayer CrI3
Kyoung-Min Kim, Do Hoon Kiem, Grigory Bednik, Myung Joon Han, and Moon Jip Park
Nano Letters Published:June 27, 2023
DOI:https://doi.org/10.1021/acs.nanolett.3c01529
Abstract
Twist engineering of van der Waals magnets has emerged as an outstanding platform for manipulating exotic magnetic states. However, the complicated form of spin interactions in the large moiré superlattice obstructs a concrete understanding of such spin systems. To tackle this problem, for the first time, we developed a generic ab initio spin Hamiltonian for twisted bilayer magnets. Our atomistic model reveals that strong AB sublattice symmetry breaking due to the twist introduces a promising route to realize the novel noncentrosymmetric magnetism. Several unprecedented features and phases are uncovered including the peculiar domain structure and skyrmion phase induced by noncentrosymmetricity. The diagram of those distinctive magnetic phases has been constructed, and the detailed nature of their transitions analyzed. Further, we established the topological band theory of moiré magnons relevant to each of these phases. By respecting the full lattice structure, our theory provides the characteristic features that can be detected in experiments.
