Magneto-optical Kerr spectra of gold induced by spin accumulation
Magneto-optical Kerr spectra of gold induced by spin accumulation
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DOI：
10.1103/physrevb.106.014410
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发表时间：
2021-09
影响因子：
3.7
通讯作者：
V. Ortiz;Sinisa Coh;Richard B. Wilson
中科院分区：
文献类型：
--
作者：
V. Ortiz;Sinisa Coh;Richard B. Wilson
本文报道了自旋积累磁激发的Au的磁光克尔效应角。我们对Au/Co异质结进行了时间分辨极性MOKE测量。在我们的实验中，Co的超快光激发驱动自旋积累到相邻的Au层中。自旋积累，连同自旋-轨道耦合，导致非零项的非对角电导率张量的Au，我们测量记录的偏振和椭圆率的光反射从Au表面的光子能量在1.3和3.1 eV之间。在接近Au的带间跃迁阈值的能量处，每A/m的克尔旋转超过1 urad。在过渡铁磁金属如Ni中，每矩克尔旋转的典型值<10 nrad/A/m，而重金属如Pt或W的预测值<13 nrad/A/m。Au的光学性质对自旋磁矩的异常敏感性使得Au成为异常灵敏的光学磁强计，在光自旋电子学技术的发展中具有潜在的应用。
We report the magneto optic Kerr effect (MOKE) angle of Au magnetically excited by spin accumulation. We perform time resolved polar MOKE measurements on Au/Co heterostructures. In our experiment, the ultrafast optical excitation of the Co drives spin accumulation into an adjacent Au layer. The spin accumulation, together with spin-orbit coupling, leads to non-zero terms in the off-diagonal conductivity tensor of Au, which we measure by recording the polarization and ellipticity of light reflected from the Au surface for photon energies between 1.3 and 3.1 eV. At energies near the interband transition threshold of Au, the Kerr rotation per A/m exceeds 1 urad. Typical values for Kerr rotation per moment in transition ferromagnetic metals like Ni are<10 nrad per A/m, while predicted values for heavy metals like Pt or W are<13 nrad per A/m. The exceptional sensitivity of the optical properties of Au to spin magnetic moments make Au to be an exceptionally sensitive optical magnetometer, with potential applications in the development of optospintronic technologies.