Spin-filter effect in normal metal/ferromagnetic insulatorormal metal/superconductor structures

摘要

Taking into account the thickness of the ferromagnetic insulator, the spin-filter effect in normal metal/ferromagnetic insulatorormal metal/superconductor (NM/FI/NM/SC) junctions is studied based on the Blonder-Tinkham-Klapwijk (BTK) theory. It is shown that a spin-dependent energy shift during the tunneling process induces splitting of the subgap resonance peaks. The spin polarization due to the spin-filter effect of the FI causes an imbalance of the peaks heights and can enhance the Zeeman splitting of the gap peaks caused by an applied magnetic field. The spin-filter effect has no contribution to the proximity-effect-induced superconductivity in NM interlayer. (c) 2006 Elsevier B.V. All rights reserved.