Kondo peaks and dips in the differential conductance of a multi-lead quantum dot: Dependence on bias conditions

Abstract

We study the differential conductance in the Kondo regime of a quantum dot coupled to multiple leads. When the bias is applied symmetrically on two of the leads ($V$ and $-V$, as usual in experiments), while the others are grounded, the conductance through the biased leads always shows the expected enhancement at {\it zero} bias. However, under asymmetrically applied bias ($V$ and $\lambda V$, with $\lambda >0$), a suppression - dip - appears in the differential conductance if the asymmetry coefficient $\lambda$ is beyond a given threshold ${\lambda }_0=\sqrt[3]{1+r}$ determined by the ratio $r$ of the dot-leads couplings. This is a recipe to determine experimentally this ratio which is important for the quantum-dot devices. This finding is a direct result of the Keldysh transport formalism. For the illustration we use a many-lead Anderson Hamiltonian, the Green functions being calculated in the Lacroix approximation, which is generalized to the case of nonequilibrium.

References in corpus (10)

• Time-dependent transport in interacting and non-interacting mesoscopic systems
• Observation of the two-channel Kondo effect
• Fano and Kondo resonance in electronic current through nanodevices
• Probing the Kondo density of states in a three-terminal quantum ring
• Measuring the Out-of-Equilibrium Splitting of the Kondo Resonance
• Kondo resonance in a multi-probe quantum dot
• Kondo effect in complex mesoscopic structures
• Non-equilibrium conductance of a three-terminal quantum dot in the Kondo regime: Perturbative Renormalization Group
• Transport through a multiply connected interacting meso-system using the Keldysh formalism
• Coulomb Blockade of a Three-terminal Quantum Dot

Cited by in corpus (3)

• Out of equilibrium transport through an Anderson impurity: Probing scaling laws within the equation of motion approach
• Quantum thermodynamics of nanoscale steady states far from equilibrium
• Coulomb oscillations of the Fano-Kondo effect and zero bias anomalies in the double dot meso-transistor