Spatial Dependence of Kondo Screening and Magnetic Anisotropy on Saturated Copper Nitride Islands

ORAL

Abstract

Co adatoms on a copper nitride surface constitute a unique system for studying the interplay between Kondo physics and anisotropy in a high spin atom (S=3/2). By using scanning tunneling spectroscopy techniques, we can determine both the energy scales of the Kondo screening and the spin excitations on a single atom. Here we study the case of Co adatoms on large nitride islands that form as the copper surface is saturated with nitrogen. These islands present a rich spatial variation of their electronic structure. We observe how changes in the electronic structure of the insulator result in dramatic changes in the spectroscopy of the cobalt adatoms: a considerable increase of the anisotropy energy occurs as the Kondo resonance disappears. These results allow us to explore in detail the interplay between these two phenomena.

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Authors

  • M. Reyes Calvo

    London Centre for Nanotechnology, UCL, London, UK

  • Jenny C. Oberg

    London Centre for Nanotechnology, UCL, UK; Department of Physics \& Astronomy, UCL, UK, London Centre for Nanotechology, Dept. of Physics and Astronomy, UCL, London, UK

  • F. Delgado

    International Iberian Nanotechnology Laboratory, Braga, Portugal

  • Joaquin Fernandez-Rossier

    International Iberian Nanotechnology Laboratory, International Iberian Nanotechnology Laboratory and Departamento de Fisica Aplicada, Universidad de Alicante, International Iberian Nanotechnology Laboratory, Braga, Portugal

  • Cyrus F. Hirjibehedin

    London Centre for Nanotechnology, Dept. of Physics \& Astronomy, Dept. of Chemistry, UCL, London, UK, London Centre for Nanotechnology, UCL, London, UK; Department of Physics \& Astronomy, UCL, London, UK; Department of Chemistry, UCL, London, UK, London Centre for Nanotechnology, Dept. of Physics and Astronomy, Dept. of Chemistry, UCL, London, UK