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Effect of magnetic anisotropy on skyrmions with a high topological number in itinerant magnets
| Title: | Effect of magnetic anisotropy on skyrmions with a high topological number in itinerant magnets |
| Authors: | Hayami, Satoru Browse this author | | Motome, Yukitoshi Browse this author →KAKEN DB |
| Keywords: | Magnetic anisotropy | | Magnetism | | Skyrmions | | Spin density waves | | Kondo lattice model |
| Issue Date: | 18-Mar-2019 |
| Publisher: | American Physical Society (APS) |
| Journal Title: | Physical review B |
| Volume: | 99 |
| Issue: | 9 |
| Start Page: | 094420 |
| Publisher DOI: | 10.1103/PhysRevB.99.094420 |
| Abstract: | We report our numerical results for the effect of magnetic anisotropy on a skyrmion crystal with a high topological number of two, which was recently discovered in an itinerant electron model [R. Ozawa, S. Hayami, and Y. Motome, Phys. Rev. Let. 118, 147205 (2017)]. By performing numerical simulations based on the kernel polynomial method and the Langevin dynamics for the Kondo lattice model on a triangular lattice, we find that the topological property remains robust against single-ion anisotropy, while the magnetic texture is deformed continuously. The resultant spin structure is characterized by three wave numbers (triple-Q state), in which the xy component of the spins forms a magnetic vortex crystal and the z component of the spins behaves as a sinusoidal wave. For a larger anisotropy, we show that the system exhibits a phase transition from a skyrmion crystal to topologically trivial phases with vanishing scalar chirality: a single-Q collinear state and double-Q noncoplanar states for the easy-axis and easy-plane anisotropy, respectively. We also examine the effect of single-ion anisotropy in an external magnetic field, and find that the field range of the skyrmion crystal is rather insensitive to the anisotropy, in contrast to another skyrmion crystal with a topological number of one whose field range is considerably extended (reduced) by the easy-axis (easy-plane) anisotropy. |
| Rights: | ©2019 American Physical Society |
| Type: | article |
| URI: | http://hdl.handle.net/2115/75583 |
| Appears in Collections: | 理学院・理学研究院 (Graduate School of Science / Faculty of Science) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
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Submitter: 速水 賢
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