Kondo Effect in a Many-Electron Quantum Ring

TL;DR

This paper studies the Kondo effect in a many-electron quantum ring, revealing its modulation by magnetic flux and gate voltages, and analyzing its dependence on the energy spectrum and tunnel coupling.

Contribution

It demonstrates the magnetic flux modulation of the Kondo effect and the control of ground-state spin via gate voltages in a quantum ring.

Findings

Kondo effect modulated by Aharonov-Bohm flux

Gate voltages alter the ring's ground-state spin

Splitting of Kondo anomaly tuned with in-plane magnetic field

Abstract

The Kondo effect is investigated in a many-electron quantum ring as a function of magnetic field. For fields applied perpendicular to the plane of the ring a modulation of the Kondo effect with the Aharonov-Bohm period is observed. This effect is discussed in terms of the energy spectrum of the ring and the parametrically changing tunnel coupling. In addition, we use gate voltages to modify the ground-state spin of the ring. The observed splitting of the Kondo-related zero-bias anomaly in this configuration is tuned with an in-plane magnetic field.