论文标题
确定复杂的自旋混合电导和从磁性绝缘体/重金属双层中自旋泵化实验的自旋扩散长度
Determining complex spin mixing conductance and spin diffusion length from spin pumping experiments in magnetic insulator/heavy metal bilayers
论文作者
论文摘要
磁性绝缘子是能源有效的旋转基质的有前途的材料。与金属同行不同，磁性绝缘体的特征是在具有重金属的双层中的界面自旋混合电导的假想部分，并且负责在旋转轨道扭矩设备中类似野外的象征。在这里，我们研究了基本的理论构建体，并制定了一种一般策略，以从铁磁共振和旋转泵送的实验结果中确定复杂的自旋混合电导。结果表明，自旋混合电导的假想部分比实际部分更重要，并且与重金属厚度的自旋混合电导的关键趋势相匹配。实验结果的解释还表明，在小厚度下，界面的贡献变得很重要，大量扩散模型无法解释结果。依赖厚度的自旋扩散长度也是必要的，这与重金属中的Elliott-yfet自旋松弛机构的划分。此外，我们在使用Spin Circuit形式上插入磁性绝缘子和重金属之间的铜层时有效地解释了实验结果。
Magnetic insulators are promising materials for the development of energy-efficient spintronics. Unlike metallic counterparts, the magnetic insulators are characterized by imaginary part of the interfacial spin mixing conductance as well in a bilayer with heavy metals and it is responsible for the field-like toque in spin-orbit torque devices. Here, we study the underlying theoretical constructs and develop a general strategy to determine the complex spin mixing conductance from the experimental results of ferromagnetic resonance and spin pumping. The results show that the imaginary part of the spin mixing conductance can be one order more than the real part and it matches the critical trend of spin mixing conductance with thickness of the heavy metal. The interpretation of experimental results also indicates that at small thicknesses the interface contribution becomes significant and bulk diffusion model cannot explain the results. A thickness-dependent spin diffusion length is necessary too that is tantamount to Elliott-Yafet spin relaxation mechanism in the heavy metals. Also, we effectively explain the experimental results while inserting a copper layer with varying thicknesses in between the magnetic insulator and the heavy metal using spin-circuit formalism.
