Kondo Effect in a Quantum Antidot

TL;DR

This paper reports Kondo-like behavior in a quantum antidot within the quantum-Hall regime, revealing correlated tunneling phenomena possibly linked to skyrmion edge reconstruction, and demonstrating the broad applicability of the Kondo effect.

Contribution

It presents the first observation of Kondo-like effects in a quantum antidot, expanding understanding of correlated electron phenomena in mesoscopic systems.

Findings

Kondo-like resonances observed in quantum antidot system

Resonances occur only in alternating Coulomb-blockaded regions

Resonances suppressed by increased temperature or bias

Abstract

We report Kondo-like behaviour in a quantum antidot (a submicron depleted region in a two-dimensional electron gas) in the quantum-Hall regime. When both spin branches of the lowest Landau level encircle the antidot in a magnetic field ($\sim 1$ T), extra resonances occur between extended edge states via antidot bound states when tunnelling is Coulomb blockaded. These resonances appear only in alternating Coulomb-blockaded regions, and become suppressed when the temperature or source-drain bias is raised. Although the exact mechanism is unknown, we believe that Kondo-like correlated tunnelling arises from skyrmion-type edge reconstruction. This observation demonstrates the generality of the Kondo phenomenon.