2017/11/20 by M. Mruczkiewicz, Paweł Gruszecki, P. Gruszecki +3 · 1 citation
Engineering · Physics and Astronomy · #Anisotropy #Condensed matter physics #Ferromagnetism #Geometric phase #Magnetic field #Magnetic properties of thin films #Magnetization #Magneto-Optical Properties and Applications #Nanodot #Physics #Quantum mechanics #Skyrmion #Soliton #Spin (aerodynamics) #Spin wave #Superconductivity #Theoretical and Computational Physics #Vortex #Vortex state #cond-mat.mes-hall
paper · pdf · doi:10.1103/physrevb.97.064418
published as Phys. Rev. B 97, 064418 (2018) · 11 pages, 9 figures
arxiv created 2017/11/20 · openalex publication_date 2018/02/21 · arxiv updated 2018/02/28 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We study azimuthal spin-wave (SW) excitations in a circular ferromagnetic nanodot in different inhomogeneous, topologically nontrivial magnetization states, specifically, vortex, Bloch-type skyrmion, and N'eel-type skyrmion states. A continuous transition between these states is realized by gradually changing the out-of-plane magnetic anisotropy and the Dzyaloshinskii-Moriya exchange interaction (DMI), and the corresponding SW spectra are calculated for each state. We observe the lifting of degeneracy of SW mode frequencies and a change in the systematics of frequency levels. The latter effect is induced by the geometric Berry phase, which occurs in SWs localized at the edge of the dot in the vortex state, and vanishes in the skyrmion states. Furthermore, channeling of edge-localized azimuthal SWs and a related large frequency splitting are observed in the skyrmion states. This is attributed to DMI-induced nonreciprocity, while the coupling of the breathing and gyrotropic modes is related to the skyrmion motion. Finally, we demonstrate efficient coupling of the dynamic magnetization to a uniform magnetic field in nanodots of noncircular symmetry in the skyrmion states.