Regensburg 2013 – scientific programme

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O: Fachverband Oberflächenphysik

O 16: Magnetic Excitations: from surfaces down to adatoms (jointly with MA)

O 16.5: Topical Talk

Monday, March 11, 2013, 17:00–17:30, H23

Theory of dynamical magnetic excitations in itinerant nanomagnets — •Samir Lounis — Institute for Advanced Simulation, Forschungszentrum Jülich, 52425 Jülich, Germany

During the past decades we witnessed an unimaginable progress in the observation and understanding of magnetic structures in nanomagnets. In comparison, our understanding of the dynamics, excitations and switching of magnetism in nanostructures is still in its infancy. In the last years inelastic low-temperature spin-polarised scanning tunneling spectroscopy has been developed and explored producing exciting new insights. In these experiments, the electrons interact with the substrate during the tunneling process, exchange energy and possibly spin angular momentum, leading to inelastic tunneling. To understand, predict and unravel the mechanisms behind these excitations, we developed a method based on first-principles. For instance, during the tunneling process, the dynamical magnetic susceptibility is computed, whose imaginary part gives the density of – , as well as the coupling of tunneling electrons with the spin-excitations that is quantified in terms of a self-energy. An overview of our investigations will be presented: 3d adatoms deposited on several metallic surfaces: Cu(100), Cu(111), Ag(111) and Pt(111) with a focus on the impact of adatoms atomic number, nature of the substrate, details of the electronic hybridization as well as the decay of the electronic signal into vacuum.

Work supported by the HGF-YIG Programme FunSiLab – Functional Nanoscale Structure Probe and Simulation Laboratory (VH-NG-717).