A Holographic View on Magnetic Skyrmions

Nanometer magnetic domains oriented by magnetic fields are currently the dominating (mass) data storage technology. Alternatively, magnetic domains can be switched in their orientation by spin currents as well as by light pulses, suggesting novel approaches for future data manipulation and storage. Yet, our current understanding of many of the underlying fundamental mechanisms of these processes is far from complete. To be able to see magnetic domains representing bits of only 10s of nm in size in real space and to be able to follow their dynamics is an important capability in this context. I will give an overview on how x-ray holography and related techniques can be employed in temporally and spatially resolving experiments to investigate dynamic magnetic phenomena on the nanoscale. I will then in particular discuss results on magnetic skyrmions in thin multilayer films. Such skyrmions are currently discussed as an option to represent the individual bits in current-driven magnetic shift registers in an approach called “racetrack memory”. The generation, transport and annihilation of individual skyrmions are fundamental operations in this context. Results on the controlled generation as well as the intrinsic dynamics of skyrmions are discussed.