Transport Properties of Co in Cu(100) from Density Functional Theory Calculations

• Autores: García Fernández, Carlos; Abufager, Paula Natalia; Lorente Palacios, Nicolas
• Año de publicación: 2017
• Idioma: inglés
• Tipo de recurso: artículo
• Materia: Transport; Ab-Initio; Cu-Co-Cu
• Institución: Consejo Nacional de Investigaciones Científicas y Técnicas

The electronic transport properties of a point-contact system formed by a single Co atom adsorbed on Cu (100) and contacted by a copper tip is evaluated in the presence of intra-atomic Coulomb interactions and spin-orbit coupling. The calculations are performed using equilibrium Green's functions evaluated within density functional theory completed with a Hubbard U term and spin-orbit interaction, as implemented in the Gollum package. We show that the contribution to the transmission between electrodes of spin-flip components is negative and scaling as λ2/Δ2 where λ is the SOC and Δ the Co atom-electrode coupling. Hence, due to this unfavorable ratio, SOC effects in transport in this system are small. However, we show that the spin-flip transmission component can increase by 2 orders of magnitude depending on the value of the Hubbard U term. These effects are particularly important in the contact regime because of the prevalence of d-electron transport, while in the tunneling regime, transport is controlled by the sp-electron transmission, and results are less dependent on the values of U and SOC. Using our electronic structure and the elastic transmission calculations, we discuss the effect of U and SOC on the well-known Kondo effect of this system.
Fil: García Fernández, Carlos. Donostia International Physics Center; España
Fil: Abufager, Paula Natalia. 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: Lorente Palacios, Nicolas. Donostia International Physics Center; España