Nonequilibrium Singlet-Triplet Kondo Effect in Carbon Nanotubes
arXiv:cond-mat/0602581 · doi:10.1038/nphys340
Abstract
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.
21 pages, 5 figures
References in corpus (6)
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Cited by in corpus (20)
- Molecular Transport Junctions: Vibrational Effects
- Quantum phase transition in a single-molecule quantum dot
- Tuning the Kondo effect with a mechanically controllable break junction
- Universal Scaling in Non-equilibrium Transport Through a Single-Channel Kondo Dot
- Electronic excitations of a single molecule contacted in a three-terminal configuration
- SU(4) and SU(2) Kondo Effects in Carbon Nanotube Quantum Dots
- Evolution of SU(4) Transport Regimes in Carbon Nanotube Quantum Dots
- Two-electron bunching in transport through a QD induced by Kondo correlations
- Kondo physics in tunable semiconductor nanowire quantum dots
- Coulomb Gas on the Keldysh Contour: Anderson-Yuval-Hamann representation of the Nonequilibrium Two Level System
- Fabry-Perot interference, Kondo effect and Coulomb blockade in carbon nanotubes
- Nonequilibrium dephasing in Coulomb blockade quantum dots
- Zero bias anomaly out of equilibrium
- Transconductance of a double quantum dot system in the Kondo regime
- Out-of-equilibrium singlet-triplet Kondo effect in a single C_60 quantum dot
- Magnetic Single-Electron Transistor as a Tunable Model System for Kondo-Destroying Quantum Criticality
- Kondo Effect in Mesoscopic Quantum Dots
- Detection of exchange interaction in STM measurements through Fanolike interference effects
- Phonon-assisted and magnetic field induced Kondo tunneling in single molecular devices
- Supplementary Information: Quantum phase transition in a single-molecule quantum dot