SKM 2021 – scientific programme
Parts | Days | Selection | Search | Updates | Downloads | Help
MA: Fachverband Magnetismus
MA 17: Skyrmions II (joint session MA/KFM)
MA 17.6: Talk
Friday, October 1, 2021, 11:30–11:45, H5
Non-linear Magnetic Response of Topological Spin Textures in Helimagnetic FeGe — Mariia Stepanova1,2, •Jan Masell3, Erik Lysne1,2, Peggy Schoenherr4, Laura Köhler5, Michael Paulsen6, Alireza Qaiumzadeh2, Naoya Kanazawa7, Achim Rosch8, Yoshinori Tokura3,7, Arne Brataas2, Markus Garst5, and Dennis Meier1,2 — 1NTNU, Trondheim, Norway — 2Center for Quantum Spintronics, NTNU, Trondheim, Norway — 3RIKEN, Wako, Japan — 4UNSW, Sydney, Australia — 5KIT, Karlsruhe, Germany — 6PTB, Berlin, Germany — 7University of Tokyo, Tokyo, Japan — 8Universität zu Köln, Köln, Germany
Chiral magnets possess a periodic layered structure which is similar to cholesteric liquid crystals, forming a wide variety of non-trivial topological defects. Using magnetic force microscopy (MFM), we resolve 1D and 2D topological defects in the near-room temperature helimagnet FeGe, including disclinations and dislocations with nonzero topological winding number, as well as three fundamental types of helimagnetic domain walls. Interestingly, in addition to their non-trivial structure, all topological defects in FeGe exhibit a pronounced non-linear magnetic response in MFM, which is not observed in regions with perfect lamellar-like order. This magnetic signature is reminiscent of the "lines of flare" that arise in cholesteric liquid crystals, suggesting local variations in magnetic susceptibility. By combining MFM and micromagnetic simulations, we investigate the origin of the magnetic signature of the topological defects and discuss possibilities to utilize the anomalous local response as read-out signal in spintronics devices.