Theory of scanning tunneling microscopy of adsorbed molecules on metallic surfaces for nearly localized atomic states

M. ROMERO AND A. A. ALIGIA

PHYSICAL REVIEW B

AMER PHYSICAL SOC

Lugar: New York; Año: 2011 vol. 83 p. 155 - 423

1098-0121

We consider a Hubbard-Anderson model which describes localized orbitals in five different sites hybridizedboth among themselves and with a continuum of extended states. A square planar geometry with an atom atthe center is used to represent TBrPP-Co molecules. When the renormalized effective hopping between sites issmall compared with a Kondo energy scale determined by the site-continuum hybridization, the system can bedescribed as a set of independent Kondo resonances, rather than molecular states. We study the crossover betweenboth regimes and analyze the spectral density of conduction electrons as a function of position. The results are inqualitative agreement with measurements of the differential conductance in a system with TBrPP-Co moleculesadsorbed on a Cu(111) surface.