Electronic theory of ultrafast spin dynamics

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The tremendous increase in storage density and read/write speed in magnetic media is reaching its physical limits. Actual read-write processes take place in the order of nanoseconds. Newly developed methods, like precessional switching, have shown the potential to reach time scales of a hundred picoseconds, while competing non-magnetic optical technologies have already demonstrated even faster switching. Therefore, the need for an upspeed of magnetic dynamics is imminent. Thus it is the goal of this project to theoretically explore and understand the physical processes, possibilities, and limitations of spin dynamics on the subpicosecond time scale. The project will be focussed on the theoretical exploration of all-optical technologies of magnetic switching, which guarantee a contact-free mode of device operation, exploiting the relativistic and quantum nature of magnetic dynamics on ultrafast time scales. Ferromagnetic metals, antiferromagnetic transition metal oxides, and small magnetic nanoparticles will be taken as prototypical materials for this theoretical investigation. The electronic theory for the quantum mechanical description of these materials will be based on both first principles and parametrized approaches in order to be able to account for the materials science and the magneto-optical aspects of ultrafast spin dynamics simultaneously.