2006/02/24 by Jens Paaske, J. Paaske, A. Rosch +8 · 1 citation
Engineering · Materials Science · Physics and Astronomy · #Graphene research and applications #Molecular Junctions and Nanostructures #Quantum and electron transport phenomena #cond-mat.str-el
paper · pdf · doi:10.1038/nphys340
published as Nature Physics, vol. 2, p.460 - 464 (2006) · 21 pages, 5 figures
arxiv created 2006/02/24 · openalex publication_date 2006/07/01 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/04
The Kondo-effect is a many-body phenomenon arising due to conduction electrons scattering off a localized spin. Coherent spin-flip scattering off such a quantum impurity correlates the conduction electrons and at low temperature this leads to a zero-bias conductance anomaly. This has become a common signature in bias-spectroscopy of single-electron transistors, observed in GaAs quantum dots as well as in various single-molecule transistors. While the zero-bias Kondo effect is well established it remains uncertain to what extent Kondo correlations persist in non-equilibrium situations where inelastic processes induce decoherence. Here we report on a pronounced conductance peak observed at finite bias-voltage in a carbon nanotube quantum dot in the spin singlet ground state. We explain this finite-bias conductance anomaly by a nonequilibrium Kondo-effect involving excitations into a spin triplet state. Excellent agreement between calculated and measured nonlinear conductance is obtained, thus strongly supporting the correlated nature of this nonequilibrium resonance.