Spin relaxation through Kondo scattering in Cu/Py lateral spin valves
Spin relaxation through Kondo scattering in Cu/Py lateral spin valves
复制标题
通过 Cu/Py 横向自旋阀中近藤散射的自旋弛豫
DOI：
10.1103/physrevb.92.220420
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发表时间：
2015
影响因子：
3.7
通讯作者：
Batley J
中科院分区：
文献类型：
--
作者：
Batley J
自旋扩散长度的温度依赖性通常反映了导致自旋弛豫的散射机制。在非磁性金属中，有理由期待埃利奥特-雅菲机制发挥作用，因此，自旋扩散长度的温度依赖关系可能与电阻率成反比。在横向自旋阀中，测量发现，在低温下，自旋扩散长度意外减少。通过测量具有ppm和ppm磁性杂质的铜制成的Py/Cu/Py横向自旋阀的输运性质，我们提取了只有在近藤效应存在的情况下才能在30K以下的自旋扩散长度。我们计算了自旋驰豫速率，并分离了磁性杂质的贡献。我们发现磁性杂质的自旋翻转几率为34%。我们的分析证明了近藤散射在自旋弛豫中的主导作用，即使在1ppm的低浓度下也是如此，因此说明了它对我们和其他人观察到的自旋扩散长度缩短的重要性。
The temperature dependence of the spin diffusion length typically reflects the scattering mechanism responsible for spin relaxation. Within nonmagnetic metals it is reasonable to expect the Elliot-Yafet mechanism to play a role and thus the temperature dependence of the spin diffusion length might be inversely proportional to resistivity. In lateral spin valves, measurements have found that at low temperatures the spin diffusion length unexpectedly decreases. By measuring the transport properties of lateral Py/Cu/Py spin valves, fabricated from Cu with magnetic impurities ofppm andppm, we extract a spin diffusion length which shows this suppression below 30 K only in the presence of the Kondo effect. We have calculated the spin-relaxation rate and isolated the contribution from magnetic impurities. We find the spin-flip probability of a magnetic impurity to be 34%. Our analysis demonstrates the dominant role of Kondo scattering in spin relaxation, even in low concentrations of order 1 ppm, and hence illustrates its importance to the reduction in spin diffusion length observed by ourselves and others.