| 研究実績の概要 |
Micromagnetic simulations for skyrmions and domain walls in the spin-spiral systems 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)].
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)].
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