Dynamical properties of nanostructured Ferromagnet - Diluted Magnetic Semiconductor Hybrids II

<p>Nanostructured hybrids of ferromagnets (FM) and diluted magnetic semiconductors (DMS) will be developed and investigated by means of time- and spatially resolved magneto-optical spectroscopy. The convincing experimental observation of the impact of the magnetic fringe field on the magnetization and the magneto-optical properties of the underlying semiconductor on a Sub-micron scale during the first project period put us now in a position to mainly con-centrate on the dynamical properties of the hybrid nanostructures.</p>

<p>From the technological point of view two challenges have to be solved. To increase the me-chanical stability, the DMS will be grown on transparent ZnSe substrates. For obtaining a re-manent out-of-plane magnetization we intend to use shape-engineering in FM nanostructures with a large saturation magnetization (Dy, Co) and nanostructured multilayers (Fe/Ge, Co/Pt), where the magnetization orientation can be adjusted by the layer sequence, respectively.</p>

<p>The main focus of research will be the dynamical properties of the hybrids. This includes eluci-dating the magnetization as well as the (carrier) spin dynamics in the DMS and the magnetiza-tion dynamics of the FM, respectively, by polarization and time-resolved magneto-optics. As a main goal during this project period we want to demonstrate the dynamical coupling of the nanostructured FM to the underyling DMS. For that purpose, FM nanostructures with a rema-nent magnetization close to the out-of-plane in-plane transition will be designed. A modula-tion of the FM magnetization will be induced by an intense pump pulse and probed by the dy-namical response of the magneto-optical properties of the underlying DMS.</p>