Kondo resonances in an Aharonov-Bohm ring with an in-line quantum dot

The properties of the ground state of a closed dot-ring system with a magnetic flux in the Kondo regime are studied theoretically by means of a one-impurity Anderson Hamiltonian. The Hamiltonian is solved by means of the slave-boson mean-field theory. It is shown that at T = 0, a suppressed Kondo effect exists in this system even when the mean level spacing of electrons in the ring is larger than the bulk Kondo temperature; the physical quantities of this system depend sensitively on both the parity of the system and the size of the ring; the rich physical behavior of this system can attributed to the coexistence of both the finite-size effect and the Kondo screening effect in this system. It is also possible to detect the Kondo screening cloud by measuring the PC or the zero field impurity susceptibility chi(imp) directly in future experiments. (C) 2003 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim