Razdolski I, Alekhin A, Martens U, Bürstel D, Diesing D, Münzenberg M, Bovensiepen U, Melnikov A
Fritz Haber Institute of Max Planck Society, Faradayweg 4-6, 14195 Berlin, Germany.
J Phys Condens Matter. 2017 May 4;29(17):174002. doi: 10.1088/1361-648X/aa63c6.
We discuss fundamental aspects of laser-induced ultrafast demagnetization probed by the time-resolved magneto-optical Kerr effect (MOKE). Studying thin Fe films on MgO substrate in the absence of electronic transport, we demonstrate how to disentangle pump-induced variations of magnetization and magneto-optical coefficients. We provide a mathematical formalism for retrieving genuine laser-induced magnetization dynamics and discuss its applicability in real experimental situations. We further stress the importance of temporal resolution achieved in the experiments and argue that measurements of both time-resolved MOKE rotation and ellipticity are needed for the correct assessment of magnetization dynamics on sub-picosecond timescales. The framework developed here sheds light onto the details of the time-resolved MOKE technique and contributes to the understanding of the interplay between ultrafast laser-induced optical and magnetic effects.
我们讨论了通过时间分辨磁光克尔效应（MOKE）探测激光诱导超快退磁的基本方面。在没有电子输运的情况下，研究了MgO衬底上的薄铁膜，我们展示了如何区分泵浦诱导的磁化强度变化和磁光系数变化。我们提供了一种用于获取真实激光诱导磁化动力学的数学形式，并讨论了其在实际实验情况下的适用性。我们进一步强调了实验中实现的时间分辨率的重要性，并认为为了在亚皮秒时间尺度上正确评估磁化动力学，需要同时测量时间分辨的MOKE旋转和椭圆率。这里开发的框架揭示了时间分辨MOKE技术的细节，并有助于理解超快激光诱导的光学和磁学效应之间的相互作用。
