中国物理B ›› 2009, Vol. 18 ›› Issue (12): 5443-5450.doi: 10.1088/1674-1056/18/12/052
蒋开明1, 王瑞强2
Wang Rui-Qiang(王瑞强)a)† and Jiang Kai-Ming(蒋开明)b)
摘要: The nonequilibrium Kondo effect is studied in a molecule quantum dot coupled asymmetrically to two ferromagnetic electrodes by employing the nonequilibrium Green function technique. The current-induced deformation of the molecule is taken into account, modeled as interactions with a phonon system, and phonon-assisted Kondo satellites arise on both sides of the usual main Kondo peak. In the antiparallel electrode configuration, the Kondo satellites can be split only for the asymmetric dot-lead couplings, distinguished from the parallel configuration where splitting also exists, even though it is for symmetric case. We also analyze how to compensate the splitting and restore the suppressed zero-bias Kondo resonance. It is shown that one can change the TMR ratio significantly from a negative dip to a positive peak only by slightly modulating a local external magnetic field, whose value is greatly dependent on the electron--phonon coupling strength.
中图分类号: (Spin polarized transport)