Mesoscopic Kondo effect of a quantum dot embedded in an Aharonov-Bohm ring with intradot spin-flip scatteringB. Dong1, 2, G. H. Ding2, H. L. Cui1, 3 and X. L. Lei2
1 Department of Physics and Engineering Physics, Stevens Institute of Technology Hoboken, NJ 07030, USA
2 Department of Physics, Shanghai Jiaotong University 1954 Huashan Road, Shanghai 200030, PRC
3 School of Optoelectronics, Information Science and Technology, Yantai University Yantai, Shandong, PRC
received 1 September 2004; accepted in final form 24 November 2004
published online 7 January 2005
We study the Kondo effect in a quantum dot embedded in a mesoscopic ring taking into account the intradot spin-flip scattering R. Based on the finite- U slave-boson mean-field approach, we find that the Kondo peak in the density of states is split into two peaks by this coherent spin-flip transition, which is responsible for some interesting features of the Kondo-assisted persistent current circulating the ring: 1) strong suppression and crossover to a sine function form with increasing R; 2) appearance of a "hump" in the R-dependent behavior for odd parity. R-induced reverse of the persistent current direction is also observed for odd parity.
72.15.Qm - Scattering mechanisms and Kondo effect.
73.23.Ra - Persistent currents.
73.23.Hk - Coulomb blockade; single-electron tunneling.
© EDP Sciences 2005