Heusler compounds are exciting materials for future spintronics applications because they display a wide range of tunable electronic and magnetic interactions. Here, we use a femtosecond laser to directly transfer spin polarization from one element to another in a half-metallic Heusler material, Co2MnGe. This spin transfer initiates as soon as light is incident on the material, demonstrating spatial transfer of angular momentum between neighboring atomic sites on time scales < 10 fs. Using ultrafast high harmonic pulses to simultaneously and independently probe the magnetic state of two elements during laser excitation, we find that the magnetization of Co is enhanced, while that of Mn rapidly quenches. Density functional theory calculations show that the optical excitation directly transfers spin from one magnetic sublattice to another through preferred spin-polarized excitation pathways. This direct manipulation of spins via light provides a path toward spintronic devices that can operate on few-femtosecond or faster time scales.

中文翻译：

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通过飞秒激光激发，在自旋电子Heusler材料中的不同元素之间直接进行光诱导的自旋转移。

Heusler化合物是未来自旋电子学应用中令人兴奋的材料，因为它们显示出各种可调的电子和磁性相互作用。在这里，我们使用飞秒激光将自旋极化从一种元素直接转移到半金属Heusler材料Co2MnGe中。一旦光入射到材料上，该自旋转移就开始，这证明了在小于10 fs的时标上相邻原子位点之间的角动量在空间上的转移。使用超快高谐波脉冲同时并独立地探测激光激发期间两个元素的磁态，我们发现Co的磁化强度得到增强，而Mn的磁化强度则迅速淬灭。密度泛函理论计算表明，光激发通过优选的自旋极化激发路径将自旋从一个磁性亚晶格直接转移到另一磁性亚晶格。通过光对自旋的这种直接操纵为通向自旋电子器件的途径提供了一条途径，该器件可以在几飞秒或更短的时间范围内运行。