2016 Fiscal Year Annual Research Report
Efficient Thermal Spin Conversion in Spin-spiral Systems
Publicly Offered Research
| Project Area | nano spin conversion science |
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| Project/Area Number |
15H01009
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| Research Institution | Tohoku University |
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Principal Investigator |
Tretiakov Oleg 東北大学, 金属材料研究所, 助教 (50643425)
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| Project Period (FY) |
2015-04-01 – 2017-03-31
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| Keywords | spin-spiral textures / curvature effects / thermal effects / spin-orbit interaction |
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| Outline of Annual Research Achievements |
We formulated a general microscopic approach to spin-orbit torques in ferromagnet/heavy-metal bilayers in linear response to electric current or electric field [Physical Review B 95, 094401 (2017)]. The torques are directly related to a local spin polarization of conduction electrons, which is computed from generalized Kubo-Streda formulas.
We have developed a multiscale magnetization dynamics simulation approach that can be applied to large systems with spin spiral structures that vary locally on small length scales [Physical Review B 94, 184415 (2016)]. We have shown that in a system with a Dzyaloshinskii-Moriya interaction leading to spin spirals, the simulated multiscale result is in good agreement with the analytical calculation.
We developed a theory of Skyrmion Hall effect, which has been successfully observed by time-resolved x-ray microscopy [Nature Physics, 13, 170 (2017)]. We find that skyrmions move at a well-defined Skyrmion Hall angle, but in contrast to conventional theoretical expectations, it increases linearly with velocity. We explained our observation based on internal mode excitations in combination with a field-like spin-orbit torque, showing that one must go beyond the usual rigid skyrmion description to understand the dynamics.
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| Research Progress Status |
28年度が最終年度であるため、記入しない。
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| Strategy for Future Research Activity |
28年度が最終年度であるため、記入しない。
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| Remarks |
Tretiakov's Group Research https://sites.google.com/site/tretiakov/
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Research Products
(21 results)
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[Journal Article] Skyrmion Hall Effect Revealed by Direct Time-Resolved X-Ray Microscopy2017
Author(s)
K. Litzius, I. Lemesh, B. Kruger, P. Bassirian, L. Caretta, K. Richter, F. Buttner, K. Sato, Oleg A. Tretiakov, J. Forster, R. M. Reeve, M. Weigand, I. Bykova, H. Stoll, G. Schutz, G. S. D. Beach, and Mathias Klaui
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Journal Title
Nature Physics
Volume: 13
Pages: 170-175
DOI
Peer Reviewed / Int'l Joint Research / Acknowledgement Compliant
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[Presentation] Antiferromagnetic Skyrmions2016
Author(s)
Oleg A. Tretiakov
Organizer
KINKEN-KIST joint seminar Future electronic materials and devices beyond Si"
Place of Presentation
Tohoku University, Sendai, Japan
Year and Date
2016-10-24 – 2016-10-25
Int'l Joint Research / Invited
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[Presentation] Antiferromagnetic Skyrmions2016
Author(s)
Oleg A. Tretiakov
Organizer
International Workshop on Antiferromagnetic Spintronics
Place of Presentation
Johannes Gutenberg-Universitat, Mainz, Germany
Year and Date
2016-09-26 – 2016-09-30
Int'l Joint Research / Invited
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