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We theoretically investigate the Kondo effect of a quantum dot embedded in a mesoscopic Aharonov-Bohm(AB)ring in the presence of the spin flip processes by means of the one-impurity Anderson Hamiltonian.Based on theslave-boson mean-field theory,we find that in this system the persistent current(PC)sensitively depends on the parityand size of the AB ring and can be tuned by the spin-flip scattering(R).In the small AB ring,the PC is suppresseddue to the enhancing R weakening the Kondo resonance.On the contrary,in the large AB ring,with R increasing,thepeak of PC firstly moves up to max-peak and then down.Especially,the PC phase shift of π appears suddenly withthe proper value of R,implying the existence of the anomalous Kondo effect in this system.Thus this system may be acandidate for quantum switch.
We theoretically investigate the Kondo effect of a quantum dot embedded in a mesoscopic Aharonov-Bohm (AB) ring in the presence of the spin flip processes by the one-impurity Anderson Hamiltonian. Based on theslave-boson mean-field theory, we find that in this system the persistent current (PC) sensitively depends on the parity and size of the AB ring and can be tuned by the spin-flip scattering (R) .In the small AB ring, the PC is suppressed to the enhancing R weakening the Kondo resonance. On the contrary, in the large AB ring, with R increasing, thepeak of PC first moves up to max-peak and then down .Especially, the PC phase shift of π appears suddenly with the proper value of R, implying the existence of the anomalous Kondo effect in this system.Thus this system may be acandidate for quantum switch.