Ultrafast Orbital-Oriented Control of Magnetization in Half-Metallic La0.7Sr0.3 MnO3 Films
Ultrafast Orbital-Oriented Control of Magnetization in Half-Metallic La0.7Sr0.3 MnO3 Films
复制标题
半金属 La0.7Sr0.3MnO3 薄膜磁化的超快轨道定向控制
DOI：
10.1002/adma.201806443
复制
发表时间：
2019-03-15
影响因子：
29.4
通讯作者：
Xu, Yongbing
中科院分区：
文献类型：
--
作者：
Liu, Bo;Niu, Wei;Xu, Yongbing
利用超快脉冲激光操纵自旋为自旋电子学的应用提供了一条新的途径。虽然自旋轨道耦合在超快激光诱导退磁中起着关键作用，但各向异性自旋轨道耦合对瞬态磁化的影响仍然是一个悬而未决的问题。利用超快泵浦-探测技术研究了半金属La_（0.2）Sr_（0.3）MnO_3薄膜中各向异性自旋轨道耦合在自旋动力学中的作用。当探测光被调谐为s-或p-偏振时，发现磁序在初始亚皮秒内分别瞬时增强或衰减。随后的缓慢退磁幅度遵循四重对称的d（x2-y2）轨道作为探测光的偏振角的函数。基于Elliott-Yafet自旋翻转散射模型，揭示了瞬态磁化增强与各向异性自旋轨道耦合产生的自旋混合态有关.这些发现为研究各向异性自旋轨道耦合磁性系统的自旋动力学提供了新的视角，也为自旋电子器件中信息过程的超快控制提供了新的视角。
Manipulating spins by ultrafast pulse laser provides a new avenue to switch the magnetization for spintronic applications. While the spin-orbit coupling is known to play a pivotal role in the ultrafast laser-induced demagnetization, the effect of the anisotropic spin-orbit coupling on the transient magnetization remains an open issue. This study uncovers the role ofanisotropic spin-orbit coupling in the spin dynamics in a half-metallic La0.2Sr0.3MnO3 film by ultrafast pump-probe technique. The magnetic order is found to be transiently enhanced or attenuated within the initial subpicosecond when the probe light is tuned to be s- or p-polarized, respectively. The subsequent slow demagnetization amplitude follows the fourfold symmetry of the d(x2-y2) orbitals as a function of the polarization angles of the probe light. A model based on the Elliott-Yafet spin-flip scatterings is proposed to reveal that the transient magnetization enhancement is related to the spin-mixed states arising from the anisotropic spin-orbit coupling. The findings provide new insights into the spin dynamics in magnetic systems with anisotropic spin-orbit coupling as well as perspectives for the ultrafast control of information process in spintronic devices.