2019 Fiscal Year Final Research Report
Topological magnons in skyrmion-lattice phases
| Project/Area Number |
17K18744
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| Research Category |
Grant-in-Aid for Challenging Research (Exploratory)
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| Allocation Type | Multi-year Fund |
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| Research Field |
Condensed matter physics and related fields
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| Research Institution | Tohoku University |
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Principal Investigator |
Sato Taku 東北大学, 多元物質科学研究所, 教授 (70354214)
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| Project Period (FY) |
2017-06-30 – 2020-03-31
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| Keywords | magnetic skyrmion / neutron scattering / small angle scattering / inelastic scattering / topological magnon |
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| Outline of Final Research Achievements |
Magnetic skyrmion lattice, a lattice of swirling topological magnetic texture, is predicted theoretically to host “topological bands” of quantized collective dynamics of magnetic moments, or “magnons”. In this study, we searched such topological magnons experimentally. First, we studied magnetic properties of various doped systems, such as Mn(Si,Ge), and found the appropriate systems to explore the topological magnons. In the neutron inelastic experiment, we observed a very broad inelastic excitation spectrum characteristic to the skyrmion lattice phase. This result is apparently not consistent with the theoretical predication, nonetheless, our numerical simulation suggests that the broadness is due to the finite temperature effect.
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| Free Research Field |
磁性・中性子散乱
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| Academic Significance and Societal Importance of the Research Achievements |
磁性体中に形成される磁気スカーミオンはその非自明なトポロジーに起因して外乱から保護された構造であると考えられるため、基礎科学の側面からだけでなく、スピントロニクス応用の観点からも興味が持たれている。本研究で我々は磁気スカーミオン中の準粒子マグノン（磁気モーメントの集団運動）に対してトポロジカルバンド形成の検証を行った。結果は予想されたものとは異なっていたが、磁気スカーミオン格子における有限温度のミクロな磁気ダイナミクスを明らかにしたという意味で基礎科学的に意義があると考える。
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