General features of photoinduced spin dynamics in ferromagnetic and ferrimagnetic compounds
General features of photoinduced spin dynamics in ferromagnetic and ferrimagnetic compounds
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DOI：
10.1103/physrevlett.94.087202
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发表时间：
2005-03-04
影响因子：
8.6
通讯作者：
Tokura, Y
中科院分区：
文献类型：
--
作者：
Ogasawara, T;Ohgushi, K;Tokura, Y
用时间分辨磁光Kerr谱研究了FeCr2S4、CoCr2S4、CuCr2Se4、CdCr2Se4、La0.6Sr0.4MnO3和SrRuO3等多种铁磁和亚铁磁性化合物的超快光致自旋动力学。在所有化合物中普遍观察到的时间退磁过程本质上由两个部分组成：一个是瞬时变化，可能起源于光激发载流子在非辐射衰变过程中的多次磁激发发射；另一个是由于自旋系统的热化而产生的延迟响应。延迟变化的时间常数强烈依赖于材料，并随磁晶各向异性的变化而变化，表明自旋-轨道耦合是这一过程的主要相互作用。
Ultrafast photoinduced spin dynamics has been investigated by time-resolved magneto-optical Kerr spectroscopy for various ferromagnetic and ferrimagnetic compounds: FeCr2S4, CoCr2S4, CuCr2Se4, CdCr2Se4, La0.6Sr0.4MnO3, and SrRuO3. The temporal demagnetization process, which is observed commonly for all the compounds, essentially consists of two components: One is an instantaneous change which originates perhaps from multiple emissions of magnetic excitations during nonradiative decay of photoexcited carriers, and the other is a delayed response due to thermalization of the spin system. The time constant of the delayed change depends strongly on materials and is scaled with the magnetocrystalline anisotropy, indicating that spin-orbit coupling is a dominant interaction for this process.