Magnetic-flux-dependent Kondo effect in a quantum dot embedded in an Aharonov-Bohm ring

The Kondo effect is examined in a quantum dot embedded in an Aharonov-Bohm (AB) ring when the size of the AB ring is much smaller than the Kondo cloud. Using the scaling method, an analytical expression is given for the Kondo temperature T_k, as a function of the AB phase φ for the magnetic flux penetrating the ring. T_k is significantly modulated by the flux. T_k is minimal when φ 0 and maximal when φ π. The scaling method also yields the logarithmic corrections to the conductance at finite temperatures of T ≫ T_k.