Tunability of the Kondo effect in an asymmetrically tunnel coupled quantum dot
Max-Planck-Institut für Festkörperforschung, Heisenbergstr. 1, 70569 Stuttgart, Germany
Corresponding author: a email@example.com
Revised: 26 April 2006
Published online: 13 June 2006
The transport properties of a single quantum dot were measured at low temperature in a regime of strong asymmetric tunnel coupling to leads. By tuning this asymmetry, the two parameters of the Kondo effect in a quantum dot, the Kondo temperature and the zero-bias zero-temperature conductance, were independently controlled. A careful analysis of the Coulomb energies and of the tunnel couplings was performed. It allowed an estimate of the Kondo temperature independently of its value obtained via the temperature dependence of the conductance. Both are in good agreement. We finally compared our experimental data with an exact solution of the Kondo problem which provides the dependence of the differential conductance on temperature and source-drain voltage. Theoretical expectations fit quite well our experimental data in the equilibrium and out-of-equilibrium regimes.
PACS: 72.15.Qn – Scattering mechanisms and Kondo effect / 73.21.La – Quantum dots / 73.23.Hk – Coulomb blockade; single-electron tunneling / 85.35.-p – Nanoelectronic devices
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2006