Tunable Non-local Coupling between Kondo Impurities

TL;DR

This paper investigates how the RKKY exchange interaction between two quantum dots in the Kondo regime can be tuned using magnetic fields and asymmetry, revealing new insights into their coupling mechanisms.

Contribution

It demonstrates the tunability of RKKY interaction and uncovers a chiral coupling in the Kondo chessboard, advancing understanding of quantum dot interactions.

Findings

Observation of Kondo resonance splitting at zero magnetic field

Measurement of RKKY interaction strength as a function of Kondo temperature asymmetry

Detection of chiral coupling between quantum dots at finite magnetic fields

Abstract

We study the tuning mechanisms of the Ruderman-Kittel-Kasuya-Yosida (RKKY) exchange interaction between two lateral quantum dots in the Kondo regime. At zero magnetic field we observe the expected splitting of the Kondo resonance and measure the RKKY interaction strength J as a function of the asymmetry between the two Kondo temperatures. At finite magnetic fields a chiral coupling between the quantum dots is observed in the Kondo chessboard and we probe the presence of the exchange interaction by analyzing the Kondo temperature with magnetic field.