title: Inelastic tunneling spectroscopy for magnetic atoms and the Kondo resonance.
abstract: The interaction between a single magnetic atom and the metal environment (including a magnetic field) is analyzed by introducing an ionic Hamiltonian combined with an effective crystal-field term, and by using a Green-function equation of motion method. This approach describes the inelastic electron tunneling spectroscopy and the Kondo resonances as due to atomic spin fluctuations associated with electron co-tunneling processes between the leads and the atom. We analyze in the case of Fe on CuN the possible spin fluctuations between states with S = 2 and 3/2 or 5/2 and conclude that the experimentally found asymmetries in the conductance with respect to the applied bias, and its marked structures, are well explained by the 2↔3/2 spin fluctuations. The case of Co is also considered and shown to present, in contrast with Fe, a resonance at the Fermi energy corresponding to a Kondo temperature of 6 K.
authors.affiliation: Instituto de Desarrollo Tecnológico para la Industria Química and Departamento de Materiales, Facultad de Ingeniería Química, CONICET-UNL, Santa Fe, Argentina. egold@intec.unl.edu.ar
authors.forename: E C
authors.initials: EC
authors.lastname: Goldberg
authors.forename: F
authors.initials: F
authors.lastname: Flores