2.12.2011, 12:00 Jungiusstr. 11, Hörsaal AP | SFB 668 - Kolloquium Prof. Antonio T. Costa (Universität Rio de Janiero): Theory of spin excitations in nanoscopic
strucutres - spin-orbit effectsWe have developed a formalism to calculate the spectra of spin
excitations of structures of nanoscopic dimensions that takes into
account spin-orbit coupling. We study structures composed by magnetic
units (adatoms, clusters, ultrathin films) deposited on metallic
substrates. The reduced symmetry of the magnetic units enhance the
effects of spin-orbit coupling and activate mechanisms such as the
Dzyaloshinskii-Moriya anti-symmetric exchange coupling. We are also
able to predict anysotropic g-factors. In the case of ultrathin films,
our formalism can span the entire Brillouin zone, being able to
describe within the same framework FMR results and spectra obtained
with SPEELS. We can also calculate the spectra that would be obtained
by local probes such as inelastic scanning tunneling spectroscopy. We
will present results for Fe ultrathin films on W(110) and for
transition metal adatoms on metallic substrates. |