Fano-Kondo effect in side-coupled double quantum dots at finite temperatures and the importance of the two-stage Kondo screening

Abstract

We study the zero-bias conductance through the system of two quantum dots, one of which is embedded directly between the source and drain electrodes, while the second dot is side-coupled to the first one through a tunneling junction. Modeling the system using the two-impurity Anderson model, we compute the temperature-dependence of the conductance in various parameter regimes using the numerical renormalization group. We consider the non-interacting case, where we study the extent of the departure from the conventional Fano resonance line shape at finite temperatures, and the case where the embedded and/or the side-coupled quantum dot is interacting, where we study the consequences of the coexistence of the Kondo and Fano effects. If the side-coupled dot is very weakly interacting, the occupancy changes by two when the on-site energy crosses the Fermi level and a Fano-resonance-like shape is observed. If the interaction on the side-coupled dot is sizeable, the occupancy changes only by one and a very different line-shape results, which is strongly and characteristically temperature dependent. These results suggest an intriguing alternative interpretation of the recent experimental results study of the transport properties of the side-coupled double quantum dot [Sasaki et al., Phys. Rev. Lett. 103, 266806 (2009)]: the observed Fano-like conductance anti-resonance may, in fact, result from the two-stage Kondo effect in the regime where the experimental temperature is between the higher and the lower Kondo temperature.

9 pages, 11 figures. In V2: updated references, 3 new figures, additional discussion

References in corpus (25)

• The numerical renormalization group method for quantum impurity systems
• Sum-rule Conserving Spectral Functions from the Numerical Renormalization Group
• Energy resolution and discretization artefacts in the numerical renormalization group
• A Numerical Renormalization Group approach to Green's Functions for Quantum Impurity Models
• Kondo effect in quantum dots
• Strongly correlated regimes in a double quantum-dot device
• Multi-impurity Anderson model for quantum dots coupled in parallel
• Interference Effects on Kondo-Assisted Transport through Double Quantum Dots
• Quantum criticality in a double quantum-dot system
• A novel approach to transport through correlated quantum dots
• Quantum phase transition in capacitively coupled double quantum dots
• Zero-field Kondo splitting and quantum-critical transition in double quantum dots
• Quantum transport through a deformable molecular transistor
• Quantum phase transitions in the systems of parallel quantum dots
• Numerical renormalization group study of two-channel three-impurity triangular clusters
• Kondo effect in double quantum dots with inter-dot repulsion
• Fermi-liquid versus non-Fermi-liquid behavior in triple quantum dots
• Two-stage Kondo effect in side-coupled quantum dots: Renormalized perturbative scaling theory and Numerical Renormalization Group analysis
• Adaptive logarithmic discretization for numerical renormalization group methods
• Conductance through an array of quantum dots
• A Novel Approach to Study Highly Correlated Nanostructures: The Logarithmic Discretization Embedded Cluster Approximation
• Kondo and Dicke effect in quantum-dots side coupled to a quantum wire
• Finite-temperature conductance signatures of quantum criticality in double quantum dots
• Correlation Effects in Side-Coupled Quantum Dots
• Transport through correlated quantum dots: An investigation using the functional renormalization group

Cited by in corpus (5)

• Suppression of Kondo screening by the Dicke effect in multiple quantum dots
• Crossover between two different Kondo couplings in side-coupled double quantum dots
• Decoherence effect on the Fano lineshapes in double quantum dots coupled between normal and superconducting leads
• Analysis of the Kondo effect in ferromagnetic atomic-sized contacts
• Tuning Fano resonances by magnetic forces for electron transport through a quantum wire side-coupled to a quantum ring