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arXiv · 1609.08955

From tunneling to contact in a magnetic atom: the non-equilibrium Kondo effect

Deung-Jang Choi·Paula Abufager·Laurent Limot·Nicolas Lorente
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Abstract

A low-temperature scanning tunneling microscope was employed to study the differential conductance in an atomic junction formed by an adsorbed Co atom on a Cu(100) surface and a copper-covered tip. A zero-bias anomaly (ZBA) reveals spin scattering off the Co atom, which is assigned to a Kondo effect. The ZBA exhibits a characteristic asymmetric lineshape when electrons tunnel between tip and sample, while upon the tip-Co contact it symmetrizes and broadens. Through density functional theory calculations and the non-equilibrium non-crossing approximation we show that the lineshape broadening is mainly a consequence of the additional coupling to the tip, while non-equilibrium effects only modify the large-bias tails of the ZBA.

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Deung-Jang Choi, Paula Abufager, Laurent Limot, Nicolas Lorente. 2016-09-28. From tunneling to contact in a magnetic atom: the non-equilibrium Kondo effect. https://doi.org/10.1063/1.4972874

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