金属结构中普通能斯特效应对自旋轨道转矩谐波霍尔测量的显著贡献
Significant ordinary Nernst effect contribution to spin-orbit torque harmonic Hall measurements in metallic structures
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中文总结 AI 辅助
该研究指出金属结构中普通能斯特效应对自旋轨道转矩谐波霍尔测量有显著贡献，以Cr/Co双层膜为例表明其会高估自旋轨道转矩效率，建议量化金属自旋轨道转矩时需谨慎考虑该效应。
中文摘要 AI 辅助
谐波霍尔测量通常用于量化铁磁体/非磁金属双层膜中的自旋轨道转矩。普通能斯特效应对二次谐波电压的贡献通常被认为可忽略，在数据分析中被省略。我们发现，在Cr/Co双层膜中，普通能斯特效应不可忽略，会导致自旋轨道转矩效率的数值被大幅高估。通过额外实验，我们估算了Cr的能斯特系数，发现其与其他金属的报道值相当。因此，当采用谐波霍尔技术量化金属中的自旋轨道转矩时，必须仔细考虑普通能斯特效应，部分过往研究的结果可能需要重新检验。
英文摘要
The harmonic Hall measurements are commonly used to quantify the spin-orbit torque in ferromagnet/normal metal bilayers. The contribution from ordinary Nernst effect to the second harmonic voltages is usually assumed to be negligible and omitted in the data analysis. We show that in Cr/Co bilayers the ordinary Nernst effect cannot be neglected and can lead to largely exaggerated values of spin-orbit torque efficiency. Conducting additional experiments, we estimate the Nernst coefficient of Cr and find it comparable to the values reported for other metals. Consequently, the ordinary Nernst effect should be carefully considered when employing the harmonic Hall technique to quantify spin-orbit torque in metals, while the results of some previous works might need to be re-examined.
