The Kondo crossover in shot noise of a single quantum dot with orbital degeneracy

Abstract

We investigate out of equilibrium transport through an orbital Kondo system realized in a single quantum dot, described by the multiorbital impurity Anderson model. Shot noise and current are calculated up to the third order in bias voltage in the particle-hole symmetric case, using the renormalized perturbation theory. The derived expressions are asymptotically exact at low energies. The resulting Fano factor of the backscattering current $F_b$ is expressed in terms of the Wilson ratio $R$ and the orbital degeneracy $N$ as $F_b=\frac{1+9(N-1)(R-1{)}^2}{1+5(N-1)(R-1{)}^2}$ at zero temperature. Then, for small Coulomb repulsions $U$, we calculate the Fano factor exactly up to terms of order $U^5$, and also carry out the numerical renormalization group calculation for intermediate $U$ in the case of two- and four-fold degeneracy ($N=2,4$). As $U$ increases, the charge fluctuation in the dot is suppressed, and the Fano factor varies rapidly from the noninteracting value $F_b=1$ to the value in the Kondo limit $F_b=\frac{N+8}{N+4}$, near the crossover region $U\sim \pi \Gamma$, with the energy scale of the hybridization $\Gamma$.

10 pages, 4 figures

References in corpus (16)

• Orbital Kondo effect in carbon nanotubes
• Universal Scaling in Non-equilibrium Transport Through a Single-Channel Kondo Dot
• SU(4) and SU(2) Kondo Effects in Carbon Nanotube Quantum Dots
• Quantum phase transition in capacitively coupled double quantum dots
• Kondo Effects in Carbon Nanotubes: From SU(4) to SU(2) symmetry
• Two-electron bunching in transport through a QD induced by Kondo correlations
• Full counting statistics for the Kondo dot in the unitary limit
• Universal Scaling of Nonequilibrium Transport in the Kondo Regime of Single Molecule Devices
• Kondo effect in double quantum dots with inter-dot repulsion
• Shot noise near the unitary limit of a Kondo quantum dot
• Current noise through a Kondo quantum dot in a SU(N) Fermi liquid state
• Shot Noise in SU(N) Quantum Dot Kondo Effects
• Fermi liquid theory for SU(N) Kondo model
• Spin polarized current and shot noise in carbon nanotube quantum dot in the Kondo regime
• Conductance via Multi orbital Kondo Effect in Single Quantum Dot
• Three-orbital Kondo effect in single quantum dot system with plural electrons

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• Delta-T noise in the Kondo regime
• Field-Enhanced Kondo Correlations in a Half-Filling Nanotube Dot: Evolution of an SU(N) Fermi-Liquid Fixed Point
• Current noise and Keldysh vertex function of an Anderson impurity in the Fermi liquid regime
• What Can We Learn from Noise? -- Mesoscopic Nonequilibrium Statistical Physics --
• Exact Green's function for a multi-orbital Anderson impurity at high bias voltages
• Thermoelectric transport and current noise through a multilevel Anderson impurity: Three-body Fermi-liquid corrections in quantum dots and magnetic alloys