Institute for Theoretical Physics, University of Regensburg, 93040 Regensburg, Germany.
Phys Rev Lett. 2011 Oct 21;107(17):176604. doi: 10.1103/PhysRevLett.107.176604. Epub 2011 Oct 20.
The spin-valve complex magnetoimpedance of symmetric ferromagnet-normal-metal-ferromagnet junctions is investigated within the drift-diffusion (standard) model of spin injection. The ac magnetoresistance-the real part difference of the impedances of the parallel and antiparallel magnetization configurations-exhibits an overall damped oscillatory behavior, as an interplay of the diffusion and spin relaxation times. In wide junctions the ac magnetoresistance oscillates between positive and negative values, reflecting resonant amplification and depletion of the spin accumulation, while the line shape for thin tunnel junctions is predicted to be purely Lorentzian. The ac spin-valve effect could be a technique to extract spin transport and spin relaxation parameters in the absence of a magnetic field and for a fixed sample size.
对称铁磁体-正常金属-铁磁体结的自旋阀复合体磁阻抗在自旋注入的漂移扩散（标准）模型内被研究。交流磁电阻——平行和反平行磁化配置的阻抗的实部差异——表现出整体阻尼的振荡行为，这是扩散和自旋弛豫时间相互作用的结果。在宽结中，交流磁电阻在正和负之间振荡，反映了自旋积累的共振放大和耗尽，而对于薄隧道结，线形状被预测为纯洛伦兹型。交流自旋阀效应可以在没有磁场和固定样品尺寸的情况下提取自旋输运和自旋弛豫参数的技术。
