Transport properties of a two Co atoms system: a theoretical approach

Ignacio J. Hamad, L. Costa Ribeiro, George Balster Martins, E. V. Anda

Published Sep 17, 2012• 0 citations

Abstract

A system of two interacting Co atoms has been studied in a recent Scanning Tunneling Microscope experiment by J. Bork et al., Nature Physics 7, 901 (2011). This kind of system has been intensively analyzed since a quantum critical point was theoretically predicted for an antiferromagnetic interacting dimer. We propose a two path structure microscopic model capable of explaining, in all the parameter space, the physics of this experiment. It consists of two atoms interacting directly and indirectly through a hopping between two electronic reservoirs that bypasses the atoms. The many-body system is treated in the finite-U Slave Boson Mean Field Approximation. Other results obtained using the Logarithmic Discretization Embedded Cluster Approximation are also discussed. The system is characterized as being in the Kondo regime for all the parameter space experimentally studied, although the effective exchange interaction between the Co atoms is antiferromagnetic.

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