Scaling analysis for Kondo effect in quantum dot embedded in Aharonov-Bohm ring

The Kondo effect is theoretically studied in a quantum dot embedded in an Aharonov-Bohm (AB) ring when the size of the ring is much smaller than the Kondo cloud. First, we construct an equivalent model in which a quantum dot is coupled to a single lead. The AB interference effect is involved in the magnetic-flux dependence of the density of states in the lead. The scaling analysis of this model yields analytical expressions for the Kondo temperature T_K and conductance at temperatures T ≫ T_K. We show that T_K may be significantly modulated by the magnetic flux penetrating the ring. Our method is generally applicable to the investigation of the Kondo effect in mesoscopic complex systems including a quantum dot.