How to get magnets small, fast

Magnetic structures on the nanometer scale are the basis for current data storage technology in hard drives. In contrast to the conventional use of external magnetic fields, ultrashort laser pulses allow to manipulate magnetization via nonequilibrium states, fueling the hope that more energy efficient process can be realized. Given that the magnetic structures need to be on the order of 10 nm small to be of technological interest, microscopic mechanisms on the few-nm scale become relevant when trying to understand the limitations of nonequilibrium pathways to generate and ultimately stabilize desired structures. I will report on studies exploring fundamental physics of nanosize magnetic structures, in particular regarding control via ultrashort laser pulses. How small and how fast can nm-domains be generated in all-optical switching processes? Magnetic Skyrmions have shown potential in this context. How does the fact that these "whirls" in the magnetization vector field are topologically non-trivial influence dynamics and switching? To put Skyrmions and other topologically non-trivial structures in thin magnetic films to use, how can we control them? Recent advances in the field will be presented, with a focus on laser-pulse mediated phenomena.