Adsorbed 3d transition-metal atoms and dimers on Au„111…: Signatures derived from one-electron calculations

MARIANA WEISSMANN; ANA MARÍA LLOIS

PHYSICAL REVIEW B

AMER PHYSICAL SOC

Lugar: New York; Año: 2001 vol. 63 p. 1134021 - 1134023

1098-0121

The spectroscopic characteristics of systems with adsorbed d impurities on noble metal surfaces should depend on the number and geometric arrangement of the adsorbed atoms and also on their d band filling. Recent experiments using scanning tunneling microscopy ~STM! have probed the electronic structure of all 3d transition-metal impurities and also of Co dimers adsorbed on Au~111!. In this contribution we correlate those experimental results with ab initio calculations and try to establish necessary conditions for observing a Kondo resonance when using the single-impurity Anderson model. We find that the relevant orbitals at the STM tip position, when it is on top of an impurity, are the d orbitals with m50 and that the energy of these levels with respect to the Fermi level determines the possibility of observing a spectroscopic feature due to the impurity.