Transport in Coupled Quantum Dots: Kondo Effect Versus Anti-Ferromagnetic Correlation

TL;DR

This paper investigates how the Kondo effect and anti-ferromagnetic interactions influence electron transport in coupled quantum dots, revealing a continuous transition between regimes and providing exact zero-temperature transport properties.

Contribution

It presents an exact analysis of transport in coupled quantum dots, demonstrating the continuous transition from Kondo to anti-ferromagnetic states as inter-dot interaction varies.

Findings

System transitions from Kondo to anti-ferromagnetic regime with increasing inter-dot interaction.

Provides exact zero-temperature conductance, charge, and spin correlations.

Shows continuous evolution of transport properties across regimes.

Abstract

The interplay between the Kondo effect and the inter-dot magnetic interaction in a coupled-dot system is studied. An exact result for the transport properties at zero temperature is obtained by diagonalizing a cluster, composed by the double-dot and its vicinity, which is connected to leads. It is shown that the system goes continuously from the Kondo regime to an anti-ferromagnetic state as the inter-dot interaction is increased. The conductance, the charge at the dots and the spin-spin correlation are obtained as a function of the gate potential.