Injection, motion, and interaction of magnetic skyrmions

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Topological objects are of interest from a fundamental and from an application point of view. As an example, magnetic skyrmions owe their topological nature to the winding of the magnetization. Skyrmions open up research areas for fundamental science, building on from fundamentals of mathematics to the realization of topologically stabilized objects for future data storage and logic devices. In our project, we will investigate the fundamental properties of skyrmion generation, movement, and interaction in a playground for magnetic skyrmion bubbles. In the envisioned spatial landscape we will conduct investigations of the possibilities and the dynamics of creation, injection, and detection of skyrmions. In the extended planar device, skyrmions will be created by magnetic field, by optical stimulation, or electrically through magnetic tunnel junctions. However, in focus will be the generation and readout via magnetic tunnel junctions. Within the two-dimensional patterns, individual skyrmions will be laterally shifted along different directions by electrical currents. The related dynamic processes and limitations will be investigated by advanced time-resolved magneto-optical imaging on different time-scales, which allows for the identification and precise observation of the moving topological objects. The well-defined setting will especially allow for the controlled interaction between individual skyrmions with the goal of generating exotic skyrmions and of studying their dynamic and annihilation behavior. By further controlling the topology at the boundaries, we will test fundamental predictions combining mathematics, magneto-optical analysis, and materials engineering. While the focus of our project lies in the experiment, we are aiming at a close collaboration between experiment and theory. Theoretical considerations will help to predict the behavior of skyrmions and give guidance on achieving modifications of the standard topology of skyrmions by manipulations of the geometry and the magnetization of boundaries. Insights will be provided to which modifications are relevant for the topology, which ones are realizable, and which ones lead to novel insights on the experiment.