Spin fluctuation effects on the conductance through a single Pd atom contact

M. A. ROMERO; S. C. GÓMEZ-CARRILLO; P. G. BOLCATTO; E. C. GOLDBERG

JOURNAL OF PHYSICS CONDENSED MATTER

Año: 2009 vol. 21 p. 2156021 - 21560211

0953-8984

A controversy about the conductance through single atoms still exists. There are many experiments where values lower than the quantum unity G0 = 2e2/h have been foundassociated to Kondo regimes with high Kondo temperatures. Specifically in the Pd single atomcontact, conductance values close to G0/2 at room temperature have been reported. In this workwe propose a theoretical analysis of a break junction of Pd where the charge fluctuation in thesingle atom contact is limited to the most probable one: d10 ↔ d9. The projected density ofstates and the characteristics of the electron transport are calculated by using a realisticdescription of the interacting system. A Kondo regime is found where the conductance valuesand their dependence on temperature are in good agreement with the experimental trendsobserved in the conduction of single molecule transistors based on transition metal coordinationcomplexes.