Inelastic cotunneling in quantum dots and molecules with weakly broken degeneracies

Abstract

We calculate the nonlinear cotunneling conductance through interacting quantum dot systems in the deep Coulomb blockade regime using a rate equation approach based on the T-matrix formalism, which shows in the concerned regions very good agreement with a generalized master equation approach. Our focus is on inelastic cotunneling in systems with weakly broken degeneracies, such as complex quantum dots or molecules. We find for these systems a characteristic gate dependence of the non-equilibrium cotunneling conductance. While on one side of a Coulomb diamond the conductance decreases after the inelastic cotunneling threshold towards its saturation value, on the other side it increases monotonously even after the threshold. We show that this behavior originates from an asymmetric gate voltage dependence of the effective cotunneling amplitudes.

12 pages, 12 figures; revised published version

References in corpus (12)

• Quantum phase transition in a single-molecule quantum dot
• Theory of the Franck-Condon blockade regime
• Tunneling through molecules and quantum dots: master-equation approaches
• Tuning the Kondo effect with a mechanically controllable break junction
• Kinetic Equations for Transport Through Single-Molecule Transistors
• Nonequilibrium Singlet-Triplet Kondo Effect in Carbon Nanotubes
• Electronic excitations of a single molecule contacted in a three-terminal configuration
• Electronic excitation spectrum of metallic carbon nanotubes
• Nonequilibrium Transport through a Kondo Dot in a Magnetic Field: Perturbation Theory
• A benzene interference single-electron transistor
• Symmetry fingerprints of a benzene single-electron transistor
• Electron transport in the four-lead two-impurity Kondo model: Nonequilibrium perturbation theory with almost degenerate levels