Nonequilibrium Cotunneling through a Three-Level Quantum Dot

Abstract

We calculate the nonlinear cotunneling conductance through a quantum dot with 3 electrons occupying the three highest lying energy levels. Starting from a 3-orbital Anderson model, we apply a generalized Schrieffer-Wolff transformation to derive an effective Kondo model for the system. Within this model we calculate the nonequilibrium occupation numbers and the corresponding cotunneling current to leading order in the exchange couplings. We identify the inelastic cotunneling thresholds and their splittings with applied magnetic field, and make a qualitative comparison to recent experimental data on carbon nanotube and InAs quantum-wire quantum dots. Further predictions of the model like cascade resonances and a magnetic-field dependence of the orbital level splitting are not yet observed but within reach of recent experimental work on carbon nanotube and InAs nanowire quantum dots.

12 pages, 13 figures

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Cited by in corpus (6)

• Kondo effects in a triangular triple quantum dot: NRG study in the whole region of the electron filling
• Kondo effects in a triangular triple quantum dot with lower symmetries
• Transport mirages in single-molecule devices
• Exchange cotunneling through quantum dots with spin-orbit coupling
• Quantum phase transition and underscreened Kondo effect in electron transport through parallel double quantum dots
• Spin and orbital fluctuations in non-equilibrium transport through quantum dots: A renormalisation-group analysis