Igarashi Junta, Remy Quentin, Iihama Satoshi, Malinowski Grégory, Hehn Michel, Gorchon Jon, Hohlfeld Julius, Fukami Shunsuke, Ohno Hideo, Mangin Stéphane
Laboratory for Nanoelectronics and Spintronics, Research Institute of Electrical Communication, Tohoku University, 2-1-1 Katahira, Aoba, Sendai 980-8577, Japan.
Institut Jean Lamour, UMR CNRS 7198, Université de Lorraine, Nancy 54011, France.
Nano Lett. 2020 Dec 9;20(12):8654-8660. doi: 10.1021/acs.nanolett.0c03373. Epub 2020 Nov 23.
Since it was recently demonstrated in a spin-valve structure, magnetization reversal of a ferromagnetic layer using a single ultrashort optical pulse has attracted attention for future ultrafast and energy-efficient magnetic storage or memory devices. However, the mechanism and the role of the magnetic properties of the ferromagnet as well as the time scale of the magnetization switching are not understood. Here, we investigate single-shot all-optical magnetization switching in a GdFeCo/Cu/[CoNi/Pt] spin-valve structure. We demonstrate that the threshold fluence for switching both the GdFeCo and the ferromagnetic layer depends on the laser pulse duration and the thickness and the Curie temperature of the ferromagnetic layer. We are able to explain most of the experimental results using a phenomenological model. This work provides a way to engineer ferromagnetic materials for energy efficient single-shot all-optical magnetization switching.
由于最近在自旋阀结构中得到证实，利用单个超短光脉冲实现铁磁层的磁化反转，已引起人们对未来超快且节能的磁存储或存储器件的关注。然而，铁磁体磁性能的机制和作用以及磁化切换的时间尺度仍不清楚。在此，我们研究了GdFeCo/Cu/[CoNi/Pt]自旋阀结构中的单次全光磁化切换。我们证明，切换GdFeCo和铁磁层的阈值能量密度取决于激光脉冲持续时间、铁磁层的厚度和居里温度。我们能够使用一个唯象模型解释大部分实验结果。这项工作为设计用于高效单次全光磁化切换的铁磁材料提供了一种方法。
