NRG calculations of the ground-state energy: application to the correlation effects in the adsorption of magnetic impurities on metal surfaces

Abstract

The ground-state energy of a quantum impurity model can be calculated using the numerical renormalization group with a modified discretization scheme, with sufficient accuracy to reliably extract physical information about the system. The approach is applied to study binding of magnetic adsorbates modeled by the Anderson-Newns model for chemisorption on metal surfaces. The correlation energy is largest in the valence-fluctuation regime; in the strong-coupling (Kondo) regime the Kondo-singlet formation energy is found to be only a minor contribution. As an application of the method to more difficult surface-science problems, we study the binding energy of a magnetic atom adsorbed near a step edge on a surface with a strongly modulated surface-state electron density. The zero-temperature magnetic susceptibility is determined from the field dependence of the binding energy, thereby providing an independent result for the Kondo temperature TK, which agrees very well with the TK extracted from a thermodynamic calculation.

4 pages

References in corpus (2)

• The numerical renormalization group method for quantum impurity systems
• Energy resolution and discretization artefacts in the numerical renormalization group

Cited by in corpus (3)

• Kondo effect at low electron density and high particle-hole asymmetry in 1D, 2D, and 3D
• Universal scaling of tunable Yu-Shiba-Rusinov states across the quantum phase transition
• Kondo physics of magnetic adatoms on metallic surfaces when the onset of the surface conduction density of states crosses the Fermi level