Kondo physics in the T-shaped structure with two detuned quantum dots

Abstract

The Kondo effect in the T-shaped double-quantum-dot structure is theoretically investigated, by considering different adjustments of the quantum dot levels. It is shown that when the quantum dot levels are shifted to the electron–hole symmetry point, the two-stage Kondo effect can be induced at the limit of weak interdot coupling. However, with the increase of interdot coupling, the interdot antiferromagnetic correlation modifies the Kondo effect efficiently, leading to the destruction of the conductance plateau. If the dot levels are detuned, the low-temperature entropy transition will exhibit new results and complicated transport behaviors occur. The reason also arises from the competition between the Kondo effect and the interdot antiferromagnetic correlation. We believe that these results are helpful for the further understanding of the Kondo physics in the T-shaped double-dot structure. • Kondo effects in the T-shaped structure are studied by considering different quantum dot levels. • When dot levels are shifted simultaneously to electron–hole symmetry point, the two-stage Kondo effect occurs. • If dot levels are detuned, entropy transition exhibits new results, leading to the discounted Kondo effect. • If one dot level is zero, Kondo effect induces various conductance results, with the shift of other dot level. • This work are helpful for further understanding the Kondo physics in T-shaped double-dot structures.