Spin and orbital fluctuations in non-equilibrium transport through quantum dots: A renormalisation-group analysis
arXiv:1007.3605 · doi:10.1209/0295-5075/92/10002
Abstract
We study non-equilibrium current and occupation probabilities of a two-orbital quantum dot. The couplings to the leads are allowed to be asymmetric and orbital dependent as it is generically the case in transport experiments on molecules and nanowires. Starting from a two-orbital Anderson model, we perform a generalised Schrieffer-Wolff transformation to derive an effective Kondo model. This generates an orbital potential scattering contribution which is of the same order as the spin exchange interaction. In a first perturbative analysis we identify a regime of negative differential conductance and a cascade resonance in the presence of an external magnetic field, which both originate from the non-equilibrium occupation of the orbitals. We then study the logarithmic enhancement of these signatures by means of a renormalisation-group treatment. We find that the orbital potential scattering qualitatively changes the renormalisation of the spin exchange couplings and strongly affects the differential conductance for asymmetric couplings.
arXiv comment6 pages, 4 figures, revised version as published
References in corpus (23)
- Spins in few-electron quantum dots
- Kondo physics in carbon nanotubes
- Quantum phase transition in a single-molecule quantum dot
- On steady-state currents through nano-devices: a scattering-states numerical renormalization group approach to open quantum systems
- Non-Equilibrium Transport through a Kondo-Dot in a Magnetic Field: Perturbation Theory and Poor Man's Scaling
- Twofold advance in the theoretical understanding of far-from-equilibrium properties of interacting nanostructures
- A perturbative nonequilibrium renormalization group method for dissipative quantum mechanics: Real-time RG in frequency space (RTRG-FS)
- Nonequilibrium Singlet-Triplet Kondo Effect in Carbon Nanotubes
- Scaling and Decoherence in the Out-of-Equilibrium Kondo Model
- Electronic excitations of a single molecule contacted in a three-terminal configuration
- Comparative study of theoretical methods for nonequilibrium quantum transport
- Nonequilibrium functional RG with frequency dependent vertex function: A study of the single impurity Anderson model
- Giant fluctuations and gate control of the g-factor in InAs Nanowire Quantum Dots
- Charge transport through single molecules, quantum dots, and quantum wires
- Nonequilibrium Transport through a Kondo Dot in a Magnetic Field: Perturbation Theory
- Nonequilibrium Transport through a Kondo Dot: Decoherence Effects
- The Kondo Effect in Non-Equilibrium Quantum Dots: Perturbative Renormalization Group
- Kondo physics in tunable semiconductor nanowire quantum dots
- Non-equilibrium current and relaxation dynamics of a charge-fluctuating quantum dot
- New method for studying steady states in quantum impurity problems: The interacting resonant level model
- Nonequilibrium Cotunneling through a Three-Level Quantum Dot
- Perturbative treatment of the multichannel interacting resonant level model in steady state non-equilibrium
- Nonequilibrium transport through parallel double quantum dots in the Kondo regime