标题： 探索Co、Fe和Ni参考层在铁磁自旋阀中单脉冲全光翻转的应用 显示英文标题

标题： Exploring Co, Fe, and Ni Reference Layers for Single-Pulse All-Optical Reversal in Ferromagnetic Spin Valves

摘要： 我们通过系统比较由纯Co、Ni和Fe组成的参考层，研究了超快激光脉冲在铁磁自旋阀中引起的磁化翻转过程。 为了克服由于参考层材料和厚度变化而引起的垂直磁各向异性的损失，我们设计了面内磁化的自旋阀。 虽然对于所有三种元素都观察到了反平行到平行的切换，但只有使用Co参考层时才会发生平行到反平行的切换，而在Ni和Fe中则不存在。 这种差异归因于参考材料的不同超快磁化动力学。 我们的结果支持这样一个假设：平行到反平行的切换需要参考层的快速重新磁化，这会产生一个与自由层磁化方向相反的显著负自旋电流，这是触发其翻转的必要条件。 显示英文摘要

摘要： We investigate the magnetization reversal process induced by a single femtosecond laser pulse in ferromagnetic spin valves by systematically comparing reference layers composed of pure Co, Ni, and Fe. To circumvent the loss of perpendicular magnetic anisotropy associated with changes in reference layer material and thickness, we design spin valves with in plane magnetizations. While antiparallel to parallel switching is observed for all three elements, parallel to antiparallel switching occurs only with a Co reference layer and is absent with Ni and Fe. This difference is attributed to the distinct ultrafast magnetization dynamics of the reference materials. Our results support the hypothesis that parallel to antiparallel switching requires a rapid remagnetization of the reference layer, which generates a substantial negative spin current polarized opposite to the free layer magnetization an essential condition for triggering its reversal.