title: Local dynamics of topological magnetic defects in the itinerant helimagnet FeGe.
abstract: Chiral magnetic interactions induce complex spin textures including helical and conical spin spirals, as well as particle-like objects such as magnetic skyrmions and merons. These spin textures are the basis for innovative device paradigms and give rise to exotic topological phenomena, thus being of interest for both applied and fundamental sciences. Present key questions address the dynamics of the spin system and emergent topological defects. Here we analyse the micromagnetic dynamics in the helimagnetic phase of FeGe. By combining magnetic force microscopy, single-spin magnetometry and Landau-Lifschitz-Gilbert simulations we show that the nanoscale dynamics are governed by the depinning and subsequent motion of magnetic edge dislocations. The motion of these topologically stable objects triggers perturbations that can propagate over mesoscopic length scales. The observation of stochastic instabilities in the micromagnetic structure provides insight to the spatio-temporal dynamics of itinerant helimagnets and topological defects, and discloses open challenges regarding their technological usage.
authors.affiliation: Department of Physics, ETH Zürich, Otto Stern Weg 1, Zurich 8093, Switzerland.
authors.forename: A
authors.initials: A
authors.lastname: Dussaux
authors.affiliation: Department of Materials, ETH Zürich, Vladimir-Prelog-Weg 4, Zurich 8093, Switzerland.
authors.forename: P
authors.initials: P
authors.lastname: Schoenherr
authors.affiliation: Department of Physics and Astronomy, Uppsala University, PO Box 516, Uppsala 75120, Sweden.
authors.forename: K
authors.initials: K
authors.lastname: Koumpouras
authors.affiliation: Department of Physics and Astronomy, Uppsala University, PO Box 516, Uppsala 75120, Sweden.
authors.forename: J
authors.initials: J
authors.lastname: Chico
authors.affiliation: Department of Physics, ETH Zürich, Otto Stern Weg 1, Zurich 8093, Switzerland.
authors.forename: K
authors.initials: K
authors.lastname: Chang
authors.affiliation: Department of Physics, ETH Zürich, Otto Stern Weg 1, Zurich 8093, Switzerland.
authors.forename: L
authors.initials: L
authors.lastname: Lorenzelli
authors.affiliation: Department of Applied Physics, University of Tokyo, Tokyo 113-8656, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Kanazawa
authors.affiliation: Department of Applied Physics, University of Tokyo, Tokyo 113-8656, Japan.|RIKEN Center for Emergent Matter Science (CEMS), Wako 351-0198, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Tokura
authors.affiliation: Institute for Theoretical Physics, Universität zu Köln, Köln D-50937, Germany.
authors.forename: M
authors.identifier: 0000-0001-5390-3316
authors.initials: M
authors.lastname: Garst
authors.affiliation: Department of Physics and Astronomy, Uppsala University, PO Box 516, Uppsala 75120, Sweden.
authors.forename: A
authors.initials: A
authors.lastname: Bergman
authors.affiliation: Department of Physics, ETH Zürich, Otto Stern Weg 1, Zurich 8093, Switzerland.
authors.forename: C L
authors.initials: CL
authors.lastname: Degen
authors.affiliation: Department of Materials, ETH Zürich, Vladimir-Prelog-Weg 4, Zurich 8093, Switzerland.|Department of Materials Science and Engineering, Norwegian University of Science and Technology, Trondheim 7491, Norway.
authors.forename: D
authors.initials: D
authors.lastname: Meier