The Kondo effect in semiconductor quantum dots

摘要

Anti-ferromagnetic spin exchange interaction between a localized magnetic moment and conduction electrons produces a conductance anomaly at low temperature, which is known as the Kondo effect. A semiconductor quantum dot allows one to study various aspects of Kondo physics because interaction parameters in a quantum dot are tunable with gate voltage, magnetic field etc. We use vertical quantum dots or "artificial atoms" to study the Kondo effect, and observe the Kondo effect enhanced by orbital degeneracy when the dots contain just a few electrons.