We propose an improved method of the equation of motion approach to study the Kondo problem in spin-dependent non-equilibrium conditions. We find that the previously introduced additional renormalization for non-equilibrium Kondo effects is not required when we use a proper decoupling scheme. Our improved formulation is then applied to address the spin-split Kondo peaks when a spin current injects into a Kondo system.
@article{arxiv.0711.4121,
title = {Kondo Resonance in the Presence of Spin-Polarized Currents},
author = {Yunong Qi and Jian-Xin Zhu and Shufeng Zhang and C. S. Ting},
journal= {arXiv preprint arXiv:0711.4121},
year = {2009}
}