Kondo effect in triple quantum dots

TL;DR

This paper investigates the Kondo effect in a system of three coupled quantum dots, revealing complex magnetic and charge behaviors, phase transitions, and conductance signatures relevant for quantum device applications.

Contribution

It provides a detailed numerical analysis of the Kondo phenomena in triple quantum dots, highlighting new phases and the impact of inter-dot coupling on electronic properties.

Findings

Identification of novel Kondo phases in triple quantum dots

Evolution of correlation functions with inter-dot coupling

Phase diagram linking magnetic states to conductance measurements

Abstract

Numerical analysis of the simplest odd-numbered system of coupled quantum dots reveals an interplay between magnetic ordering, charge fluctuations and the tendency of itinerant electrons in the leads to screen magnetic moments. The transition from local-moment to molecular-orbital behavior is visible in the evolution of correlation functions as the inter-dot coupling is increased. Resulting novel Kondo phases are presented in a phase diagram which can be sampled by measuring the zero-bias conductance. We discuss the origin of the even-odd effects by comparing with the double quantum dot.