Regensburg 2019 – wissenschaftliches Programm

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MA: Fachverband Magnetismus

MA 41: Magnetic Textures: Statics and Imaging II

MA 41.2: Vortrag

Donnerstag, 4. April 2019, 09:45–10:00, H37

Thermal stability of skyrmions in chiral magnets and frustrated magnets — Benjamin Heil, Achim Rosch, and •Jan Masell — Institut für Theoretische Physik, Universität zu Köln, Köln, Deutschland

Magnetic skyrmions are particle-like textures in the magnetization which are characterized by a topological winding number. Skyrmions have been observed on scales ranging from nano- to micrometers and from cryogenic temperatures up to room temperature. The combination of properties like small size, topological quantization, and efficient manipulation makes them interesting candidates for applications in future information technology devices.

The topological winding number implies that - in a continuous model for the magnetization - a skyrmion can not be erased smoothly. This property is often argued to provide them with an extraordinary stability against thermal fluctuations. We calculate the minimal energy barrier for the destruction/creation of two species of skyrmions which are stabilized by (i) Dzyaloshinskii-Moriya or (ii) frustrated exchange interactions. We show that the energy barriers remain finite even in the continuous limit and provide an expression for the saddle point configuration. In particular we show that, in the absence of frustration, the micromagnetic saddle point is independent of the external magnetic field.