| Project/Area Number |
17K05511
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Multi-year Fund |
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| Section | 一般 |
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| Research Field |
Condensed matter physics II
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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) |
2017-04-01 – 2019-03-31
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| Project Status |
Discontinued (Fiscal Year 2018)
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| Budget Amount *help |
¥4,420,000 (Direct Cost: ¥3,400,000、Indirect Cost: ¥1,020,000)
Fiscal Year 2019: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000)
Fiscal Year 2018: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000)
Fiscal Year 2017: ¥2,080,000 (Direct Cost: ¥1,600,000、Indirect Cost: ¥480,000)
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| Keywords | Antiferromagnets / Skyrmions / antiferromagnets |
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| Outline of Annual Research Achievements |
We demonstrated that the nontrivial magnetic texture of antiferromagnetic Skyrmions promotes a nonvanishing topological spin Hall effect on the flowing electrons. This effect results in a substantial enhancement of the nonadiabatic torque and, hence, improves the Skyrmion mobility [Phys. Rev. Lett. 121, 097204 (2018)]. Furthermore, we identified the dynamics of the antiferromagnetic skyrmion induced by a magnetic anisotropy gradient [Phys. Rev. B 98, 134448 (2018)]. We also showed that skyrmion-based spin torque nano-oscillators are potential next-generation microwave signal generators. We proposed to use the circular motion of an antiferromagnetic skyrmion to create an oscillation signal to overcome this obstacle. Furthermore, the speed of the circular motion for an antiferromagnetic skyrmion in a nanodisk was analytically derived and agreed well with simulations [Appl. Phys. Lett. 114, 042402 (2019)].
Micromagnetic simulations for skyrmions and domain walls in the system with Dzyaloshinskii-Moriya interaction were performed and an analytical theory for domain wall motion resulted in Phys. Rev. B 99, 060407(R) (2019). We studied the structure and dynamics of magnetic domains in synthetic antiferromagnets based on Co/Ru/Co films. We have shown that dramatic effects arise from the interaction among the topological defects comprising the dual domain walls in these structures. These features allowed us to work on the enhanced control of domain-wall motion in synthetic antiferromagnets with the potential for future devices [Sci. Rep. 8, 15794 (2018)].
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