Resonance Kondo Tunneling through a Double Quantum Dot at Finite Bias

TL;DR

This paper investigates how resonance Kondo tunneling can occur in a double quantum dot system at finite bias, revealing new conductance features and the role of decoherence effects.

Contribution

It introduces a theoretical framework using renormalization group techniques to analyze resonance Kondo tunneling in SO(4) symmetric double quantum dots at finite bias.

Findings

Resonance Kondo tunneling can occur at strong bias compensating singlet/triplet excitation energy.

Differential conductance exhibits characteristic dependence on bias and temperature.

Decoherence effects influence the shape of conductance lines.

Abstract

It is shown that the resonance Kondo tunneling through a double quantum dot (DQD) with even occupation and singlet ground state may arise at a strong bias, which compensates the energy of singlet/triplet excitation. Using the renormalization group technique we derive scaling equations and calculate the differential conductance as a function of an auxiliary dc-bias for parallel DQD described by SO(4) symmetry. We analyze the decoherence effects associated with the triplet/singlet relaxation in DQD and discuss the shape of differential conductance line as a function of dc-bias and temperature.