We study the non-equilibrium regime of the Kondo effect in a quantum dot laterally coupled to a narrow wire. We observe a split Kondo resonance when a finite bias voltage is imposed across the wire. The splitting is attributed to the creation of a double-step Fermi distribution function in the wire. Kondo correlations are strongly suppressed when the voltage across the wire exceeds the Kondo temperature. A perpendicular magnetic field enables us to selectively control the coupling between the dot and the two Fermi seas in the wire. Already at fields of order 0.1 T only the Kondo resonance associated with the strongly coupled reservoir survives.
@article{arxiv.cond-mat/0203146,
title = {Kondo effect out of equilibrium in a mesoscopic device},
author = {S. De Franceschi and R. Hanson and W. G. van der Wiel and J. M. Elzerman and J. J. Wijpkema and T. Fujisawa and S. Tarucha and L. P. Kouwenhoven},
journal= {arXiv preprint arXiv:cond-mat/0203146},
year = {2007}
}