Indirect excitation of ultrafast demagnetization.
Indirect excitation of ultrafast demagnetization.
复制标题
超快消灭的间接激发。
DOI：
10.1038/srep18970
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发表时间：
2016-01-06
影响因子：
4.6
通讯作者：
Lüning J
中科院分区：
文献类型：
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作者：
Vodungbo B;Tudu B;Perron J;Delaunay R;Müller L;Berntsen MH;Grübel G;Malinowski G;Weier C;Gautier J;Lambert G;Zeitoun P;Gutt C;Jal E;Reid AH;Granitzka PW;Jaouen N;Dakovski GL;Moeller S;Minitti MP;Mitra A;Carron S;Pfau B;von Korff Schmising C;Schneider M;Eisebitt S;Lüning J
超快磁化的激发是否需要光泵脉冲的光子与磁性层之间的直接相互作用？在这里，我们明确地证明事实并非如此。为此，我们研究了覆盖有红外不透明铝层的铁磁钴/钯多层的磁化动力学。在强烈的飞秒短红外激光脉冲激发下，薄膜表现出经典的超快退磁现象，尽管只有极少量的红外光子穿透铝层。与未覆盖的钴/钯参考薄膜相比，覆盖的薄膜的初始退磁发生延迟且速率较慢。这两个观察结果在质量上都符合通过铝膜的激发热电子从铝层到下面的磁性膜的能量传输。因此，我们的数据证实了最近的理论预测。
Does the excitation of ultrafast magnetization require direct interaction between the photons of the optical pump pulse and the magnetic layer? Here, we demonstrate unambiguously that this is not the case. For this we have studied the magnetization dynamics of a ferromagnetic cobalt/palladium multilayer capped by an IR-opaque aluminum layer. Upon excitation with an intense femtosecond-short IR laser pulse, the film exhibits the classical ultrafast demagnetization phenomenon although only a negligible number of IR photons penetrate the aluminum layer. In comparison with an uncapped cobalt/palladium reference film, the initial demagnetization of the capped film occurs with a delayed onset and at a slower rate. Both observations are qualitatively in line with energy transport from the aluminum layer into the underlying magnetic film by the excited, hot electrons of the aluminum film. Our data thus confirm recent theoretical predictions.