Electron Transport Through Coupled Quantum Dots Below the Kondo Temperature

Abstract

Conductance G, through coupled quantum dots in series isinvestigated below the Kondo temperature, based on the slaveboson formalism of the Anderson model with theantiferromagnetic spin–spin coupling J. Electron transport ischaracterized by the ratio of the dot–dot tunneling couplingV C to the level broadening in the dots Δ(dot-lead coupling). When V C /Δ 1, the Kondo levelsare split below and above the Fermi level in the leads for lowgate voltages. The gate voltage dependence of G has a broadpeak, which is fairly robust against J. This broad peak isdivided into two peaks when the energy levels are differentbetween the dots.