Study for emergent spin-orbit phenomena based on atomic-scale multipole ordering

2023 Fiscal Year Final Research Report

• Project/Area Number: 19K03752
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 13030:Magnetism, superconductivity and strongly correlated systems-related
• Research Institution: Meiji University
• Principal Investigator: Kusunose Hiroaki 明治大学, 理工学部, 専任教授 (00292201)
• Co-Investigator(Kenkyū-buntansha): 速水 賢 東京大学, 大学院工学系研究科(工学部), 講師 (20776546)
• Project Period (FY): 2019-04-01 – 2024-03-31
• Keywords: 多極子基底 / スピン軌道物性 / 交差相関応答 / マテリアルデザイン / 反強磁性

Outline of Final Research Achievements

In this project, we have investigated the emergent spin-orbit coupling, which arises from the coupling between a proper crystal structure and antiferro magnetism. We have elucidated the mechanism and the conditions for emergent spin-orbit coupling in cases of collinear and non-collinear spin structure, and have summarized the symmetry of cluster units, and the essential gradients for spin-current generation, anomalous Hall effect, etc. We have also developed the software that can perform symmetry decomposition of the model Hamiltonian by means of symmetry-adapted multipole basis. We have also formulated to extract essential model parameters from linear and nonlinear response functions. These results have led to the world-wide trend in antiferromagnetism that is called "altermagnetism".

Free Research Field

物性理論

Academic Significance and Societal Importance of the Research Achievements

軽元素を含む化合物においてもスピン軌道相互作用に由来する多彩な交差相関応答が期待できることを示した。また、その系統的な分析方法を整備した本研究の成果は、物質の機能性と結晶構造の対称性を系統的に結びつけており、マテリアルデザインの分野に新しい方法論を提供するという意義がある。また、強磁性体に比べて応用的視点の乏しかった反強磁性体が、特徴的な結晶構造と結びつくだけで、多機能性を有することを知らしめたという社会的意義がある。