Tunable Non-local Spin Control in a Coupled Quantum Dot System

TL;DR

This paper demonstrates tunable non-local spin control in a coupled quantum dot system by manipulating Kondo resonances, offering a potential method for quantum information processing.

Contribution

It presents the experimental realization of a two-impurity Kondo system in quantum dots and shows non-local control of spin states through electron number and coupling adjustments.

Findings

Suppressed and split Kondo resonances in one quantum dot via control of the other.

Evidence of non-local spin control in a coupled quantum dot system.

Potential application in quantum information processing.

Abstract

The effective interaction between magnetic impurities in metals that can lead to various magnetic ground states often competes with a tendency for electrons near impurities to screen the local moment (Kondo effect). The simplest system exhibiting the richness of this competition, the two-impurity Kondo system, is here realized experimentally in the form of two quantum dots coupled through an open conducting region. We demonstrate non-local spin control by suppressing and splitting Kondo resonances in one quantum dot by changing electron number and coupling of the other dot. Results suggest an approach to non-local spin control relevant to quantum information processing.