论文标题
Engineering Co $ _2 $ mnal $ _x $ si $ _ {1-x} $ heusler化合物作为一个模型系统，以将自旋极化，内在的吉尔伯特抑制和超级反应灭绝
Engineering Co$_2$MnAl$_x$Si$_{1-x}$ Heusler compounds as a model system to correlate spin polarization, intrinsic Gilbert damping and ultrafast demagnetization
论文作者
论文摘要
用于开发更好的自旋应用程序的磁性材料的工程依赖于两个关键参数的控制：自旋极化和吉尔伯特抑制作用负责旋转角动量耗散。预计它们都会影响在飞秒时间尺度上发生的超快磁化动力学。在这里，我们使用工程化的CO2MnalxSI1-X Heusler化合物来将自旋极化P的程度从60％调整到100％，并研究其与阻尼的相关性。我们在实验上证明，当对二氧化碳的自旋极化从1.1 10-3增加到63％自旋极化为半石磁铁CO2MNSI的超低值时，阻尼减少了。这使我们研究了这两个参数与超铁的超快消除时间之间的关系，这些时间表征了飞秒激光脉冲激发后发生的磁化损失。观察到反电磁时间与1-P成反比，因此磁阻尼可以归因于旋转角动量耗散过程的相似性，负责这两种效果。总的来说，我们的高质量赫斯勒化合物允许控制带结构，因此可以控制旋转角动量耗散的通道。
Engineering of magnetic materials for developing better spintronic applications relies on the control of two key parameters: the spin polarization and the Gilbert damping responsible for the spin angular momentum dissipation. Both of them are expected to affect the ultrafast magnetization dynamics occurring on the femtosecond time scale. Here, we use engineered Co2MnAlxSi1-x Heusler compounds to adjust the degree of spin polarization P from 60 to 100% and investigate how it correlates with the damping. We demonstrate experimentally that the damping decreases when increasing the spin polarization from 1.1 10-3 for Co2MnAl with 63% spin polarization to an ultra-low value of 4.10-4 for the half-metal magnet Co2MnSi. This allows us investigating the relation between these two parameters and the ultrafast demagnetization time characterizing the loss of magnetization occurring after femtosecond laser pulse excitation. The demagnetization time is observed to be inversely proportional to 1-P and as a consequence to the magnetic damping, which can be attributed to the similarity of the spin angular momentum dissipation processes responsible for these two effects. Altogether, our high quality Heusler compounds allow controlling the band structure and therefore the channel for spin angular momentum dissipation.
