Regensburg 2016 – wissenschaftliches Programm

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MA: Fachverband Magnetismus

MA 28: Surface Magnetism I (jointly with O)

MA 28.9: Vortrag

Mittwoch, 9. März 2016, 11:45–12:00, H31

Dynamical para-spin-excitations in non-magnetic adatoms — •Julen Ibañez-Azpiroz, Manuel dos Santos Dias, Stefan Blügel, and Samir Lounis — Peter Grünberg Institute and Institute for Advanced Simulation, Forschungszentrum Jülich and JARA, D-52425 Jülich, Germany

We find the presence of spin-excitation modes in non-magnetic adatoms, i.e. para-spin-excitation modes, the analogous of paramagnons in bulk materials. We show that their signature in the excitation spectrum can evolve a well-defined peak whose linewidth (i.e. inverse lifetime) is predominantly controled by the Stoner exchange parameter and the density of states near the Fermi level. Utilizing time-dependent density functional theory as implemented in the Korringa-Kohn-Rostoker Green function formalism, we explore the para-spin-excitations of various 4d transition-metal adatoms deposited on metallic substrates. Based on the Anderson impurity model, we identify the most favourable parameter setup for the appearance of such excitations. Finally, we simulate tunneling transport experiments to address the possibility of detecting these para-spin-excitations in inelastic scanning tunneling spectroscopy.

Funding provided by HGF-YIG Programme VH-NG-717 (Funsilab) and and the Impuls und Vernetzungsfonds der Helmholtz-Gemeinschaft (Postdoc Programm).