Cálculo de espectros de fotoemissão eletrônica de um dímero adsorvido em metal / Electronic photoemission spectra of a dimmer embedded in a metal

AUTOR(ES)

Valter Luiz Libero

DATA DE PUBLICAÇÃO

1989

RESUMO

The Renormalization Group technique developed by Wilson in 1975 is used to calculate photoemission spectra (XPS) for a dimer adsorbed on a metal; our model for this system comprises two deep levels, separated by a distance R, coupled to each other, and interacting electrostatically with the sorbate. The inversion symmetry is used to define two electronics currents, coming from the bonding and anti-bonding orbitals of the dimer, respectively. Near threshold each spectrum follow a power law; the exponents are calculated and expressed (by universal laws) in terms of the phase shifts of the conduction electrons. If the distance R between the levels is zero, the spectrum associated to the bonding orbital has a singularity at ω - ωT = Δ, where Δ is the electronic tunneling rate between the deep levels. For increasing R, the singularity is smoothed out, due to the non-radiative decay of an electron from the anti-bonding to the bonding orbital, which makes finite the lifetime of the hole created by the x-ray. This work presents the first accurate calculation of the renormalization of the tunneling rate by this non-radiative decay.

ASSUNTO(S)

grupo de renormalização spectral density densidade espectral tunneling tunelamento renormalizations group

Documentos Relacionados

• Cálculo de espectros de fotoemissão por raios-x de íons adsorvidos em metais.
• Simulação computacional de espectros de Ressonância Paramagnética Eletrônica de onda contínua.
• Efeitos topográficos em espectros RBS
• Observação de superficies por microscopia eletronica de fotoemissão (PhEEM)
• Fotoemissão no Modelo de Anderson para compostos de terras-raras com valência flutuante.