Kondo Physics and Exact Solvability of Double Dots Systems

TL;DR

This paper investigates two double quantum dot configurations, providing exact solutions via Bethe ansatz and analyzing their Kondo effects and conductance behaviors, revealing complex many-body phenomena and non-trivial sum rules.

Contribution

It presents an exact Bethe ansatz solution for double dot systems and analyzes their Kondo physics and conductance properties.

Findings

Multiple Kondo effects observed in parallel dots

Conductance zeros in the mixed valence regime

Non-trivial Friedel sum rule behavior

Abstract

We study two double dot systems, one with dots in parallel and one with dots in series, and argue they admit an exact solution via the Bethe ansatz. In the case of parallel dots we exploit the exact solution to extract the behavior of the linear response conductance. The linear response conductance of the parallel dot system possesses multiple Kondo effects, including a Kondo effect enhanced by a nonpertubative antiferromagnetic RKKY interaction, has conductance zeros in the mixed valence regime, and obeys a non-trivial form of the Friedel sum rule.