Theoretical search and control of toroidal moment hidden in magnetic states with strong spin-orbit coupling

2017 Fiscal Year Final Research Report

• Project/Area Number: 16H06590
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Single-year Grants
• Research Field: Condensed matter physics II
• Research Institution: Hokkaido University
• Principal Investigator: Hayami Satoru 北海道大学, 理学研究院, 助教 (20776546)
• Project Period (FY): 2016-08-26 – 2018-03-31
• Keywords: 強相関電子系 / 磁性 / 反対称スピン軌道相互作用 / トロイダルモーメント / 多極子 / 局所的な反転対称性の破れ / マルチフェロイクス / 遍歴電子系

Outline of Final Research Achievements

We microscopically formulated toroidal moments in the absence of time-reversal and spatial inversion symmetries. We also investigated how to observe and control toroidal moments in experiments from the theoretical side. (1)We derived an effective spin-orbit coupling under the toroidal ordering for the model including the crystalline-electric field, atomic spin-orbit coupling, and electron correlation by perturbative analysis. (2) We clarified that toroidal moments are induced around the nonmagnetic impurity site in the ferromagnets with the strong spin-orbit coupling on the triangular lattice. (3) We examined the 5d transition oxide KOsO4, which is a potential candidate showing toroidal moments.

Free Research Field

物性理論