Spin-orbital Kondo effect in a parallel double quantum dot

TL;DR

This paper investigates the spin-orbital Kondo effect in a parallel double quantum dot, revealing complex resonance structures and the interplay of spin and orbital degrees of freedom in electron transport.

Contribution

It provides experimental insights into the two-orbital Kondo effect involving both spin and orbital degeneracies in a double quantum dot system.

Findings

Kondo effect observed at interdot Coulomb blockade with degeneracies

Triple-peak Kondo resonance when orbital degeneracy is lifted

Both spin and orbital contributions influence the Kondo resonance

Abstract

Transport properties of the two-orbital Kondo effect involving both spin and orbital (pseudospin) degrees of freedom were examined in a parallel double quantum dot with a sufficient interdot Coulomb interaction and negligibly small interdot tunneling. The Kondo effect was observed at the interdot Coulomb blockade region with degeneracies of both spin and orbital degrees of freedom. When the orbital degeneracy is lifted by applying a finite detuning, the Kondo resonance exhibits a triple-peak structure, indicating that both spin and orbital contributions are involved.