SPICE Workshop on Spin textures: Magnetism meets Plasmonics, July 23rd - 25th 2024
Aisha Aqeel
Magnetic skyrmions are promising candidates as information carriers for future memory applications. These are particle-like topological solitons that can be envisaged as nanosized twists or knots in an otherwise uniform magnetic material. Skyrmions are found in chiral magnets with no inversion symmetry due to finite Dzyaloshinskii-Moriya interaction (DMI). The complex three-dimensional internal structure of magnetic skyrmions and their interaction with each other are imposed by a surrounding magnetic state of the host magnetic material. The detailed understanding of the dynamic magnetization of skyrmions in chiral magnets is crucial for their embodiment in practical devices. We investigated the magnetization dynamics of low-temperature skyrmion state (LTS) [1,2] in a chiral magnetic insulator Cu2OSeO3 by broadband microwave spectroscopy. By combining results with the linear spin wave theory, we clearly identify the dynamic modes associated with skyrmions. Interestingly, our findings suggest that under decreasing fields the hexagonal skyrmion lattice becomes unstable, resulting in the formation of the elongated skyrmions [3]. These findings highlight how the study of dynamic properties may provide valuable insights to static properties, such as microscopic nature of magnetic textures. Furthermore, we investigated the magnetization dynamics within heterostructures composed of a single crystal of Cu2OSeO3 and a polycrystalline ferromagnet NiFe (Py) thin film [4]. We have identified significant variations in the field dependence of LTS phase within the
heterostructures. An important finding is that depositing Py onto Cu2OSeO3 eliminates the need for a specific field cycling protocol to induce the LTS phase [1,3], as can be observed without any field cycling. These findings carry substantial implications for future experiments
focusing on the surface engineering of skyrmions in bilayer systems.
[1] A. Chacon, et al., Nature Physics 14, pages936–941 (2018),
[2] M. Halder, et al., Phys. Rev. B 98, 144429 (2018),
[3] A. Aqeel, et al., Phys. Rev. Lett. 126, 017202 (2021).
[4] C. Luethi, L. Flacke, A. Aqeel, et al., Appl. Phys. Lett. 122, 012401 (2023)