Spatial and Spectroscopic Profiles of the Kondo Resonance for a Single Magnetic Atom on a Metal Surface under an External Magnetic Field

Abstract

Manifestations of the Kondo effect on an atomic length scale on and around a magnetic atom adsorbed on a nonmagnetic metal surface differ depending on which spectroscopic mode the scanning tunneling microscope is operated. In a series of reports, we showed that the Kondo effect can be directly observed as protrusions (peaks) in the spatial distribution of the tunneling current, and that the protrusions (peaks) observed in the spatial distribution of the tunneling current correspond to the resonances observed in the differential conductance spectra. In this report, we show that upon applying an external magnetic field with increasing magnitude, the protrusions (peaks) observed in the spin-resolved spatial distribution of the tunneling current would decrease monotonically for spin-down electrons, but change non-monotonically for spin-up electrons. We also show that, upon applying an external magnetic field, additional features about the Fermi level appear for the narrow dip structure observed for the corresponding differential conductance spectra.