Tunable Kondo Effect of a Three-Terminal Transport Quantum Dot Embedded in an Aharonov--Bohm Ring

We theoretically investigate the Kondo effect of a three-terminal transport quantum dot (QD) embedded in an Aharonov--Bohm ring in the Kondo regime by means of the one-impurity Anderson Hamiltonian. The Hamiltonian is solved by means of the slave-boson mean-field theory. We find that in this system, the Kondo effect depends sensitively on the parity and size of the ring; the Kondo screening cloud can be tuned by tuning the coupling strength of the reservoir-dot. Thus this model might be a candidate for future device applications.