Spin current in ferromagnet/insulator/superconductor junctions
摘要
A theory of spin polarized tunneling spectroscopy based on a scattering theory is given for tunneling junctions between ferromagnets and d-wave superconductors. The spin filtering effect of an exchange field in the insulator is also treated. We clarify that the properties of the Andreev reflection are largely modified due to a presence of an exchange field in the ferromagnets, and consequently the Andreev reflected quasiparticle shows an evanescent-wave behavior depending on the injection angle of the quasiparticle. Conductance formulas for the spin current as well as the charge current are given as a function of the applied voltage and the spin-polarization in the ferromagnet for arbitrary barrier heights. It is shown that the surface bound states do not contribute to the spin current and that the zero-bias conductance peak expected for a d-wave superconductor splits into two peaks under the influence of the exchange interaction in the insulator.
引用
@article{arxiv.cond-mat/9812160,
title = {Spin current in ferromagnet/insulator/superconductor junctions},
author = {S. Kashiwaya and Y. Tanaka and N. Yoshida and M. R. Beasley},
journal= {arXiv preprint arXiv:cond-mat/9812160},
year = {2009}
}
备注
14 pages, 11 figures