Transport properties of a two-impurity system: A theoretical approach

• Autores: Hamad, Ignacio Javier; Costa Ribeiro, L.; Martins, G. B.; Anda, E. V.
• Año de publicación: 2013
• Idioma: inglés
• Tipo de recurso: artículo
• Materia: COULOMB BLOCKADE; QUANTUM DOTS; SCATTERING MECHANISMS AND KONDO EFFECT
• Institución: Consejo Nacional de Investigaciones Científicas y Técnicas

A system of two interacting cobalt atoms, at varying distances, was studied in a recent scanning tunneling microscope experiment by Bork. We propose a microscopic model that explains, for all experimentally analyzed interatomic distances, the physics observed in these experiments. Our proposal is based on the two-impurity Anderson model, with the inclusion of a two-path geometry for charge transport. This many-body system is treated in the finite-U slave boson mean-field approximation and the logarithmic-discretization embedded-cluster approximation. We physically characterize the different charge transport regimes of this system at various interatomic distances and show that, as in the experiments, the features observed in the transport properties depend on the presence of two impurities but also on the existence of two conducting channels for electron transport. We interpret the splitting observed in the conductance as the result of the hybridization of the two Kondo resonances associated with each impurity.
Fil: Hamad, Ignacio Javier. Pontifícia Universidade Católica do Rio de Janeiro; Brasil. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Física de Rosario. Universidad Nacional de Rosario. Instituto de Física de Rosario; Argentina
Fil: Costa Ribeiro, L.. Centro Federal de Educação Tecnológica; Brasil
Fil: Martins, G. B.. Oakland University; Estados Unidos
Fil: Anda, E. V.. Pontifícia Universidade Católica do Rio de Janeiro; Brasil