All‐optical ultrafast magnetization switching in magnetic material thin film without the assistance of an applied external magnetic field is explored for future ultrafast and energy‐efficient magnetic storage and memories. It is shown that femtosecond (fs) light pulses induce magnetization reversal in a large variety of magnetic materials. However, so far, only GdFeCo‐based ferrimagnetic thin films exhibit magnetization switching via a single optical pulse. Here, the single‐pulse switching of Co/Pt multilayers within a magnetic spin‐valve structure ([Co/Pt]/Cu/GdFeCo) is demonstrated and four possible magnetic configurations of the spin valve can be accessed using a sequence of single fs light pulses. The experimental study reveals that the magnetization final state of the ferromagnetic [Co/Pt] layer is determined by spin‐polarized currents generated by the light pulse interactions with the GdFeCo layer. This work provides an approach to deterministically switch ferromagnetic layers and a pathway to engineering materials for opto‐magnetic multi‐bit recording.

中文翻译：

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自旋传输介导的单次多级全光磁化开关

探索了磁性材料薄膜中的全光超快磁化切换，无需借助外部磁场即可实现未来超快和节能的磁存储和存储。结果表明，飞秒（fs）光脉冲在多种磁性材料中引起磁化反转。但是，到目前为止，仅基于GdFeCo的亚铁磁性薄膜会通过单个光脉冲显示出磁化强度转换。在此，演示了磁性自旋阀结构（[Co / Pt] / Cu / GdFeCo）中的Co / Pt多层的单脉冲切换，并且可以使用一系列单个fs访问自旋阀的四种可能的磁性配置光脉冲。实验研究表明，铁磁[Co / Pt]层的磁化最终状态由光脉冲与GdFeCo层相互作用产生的自旋极化电流决定。这项工作提供了确定性地切换铁磁层的方法，并提供了用于光磁多位记录的工程材料的途径。