Analysis of the time-resolved magneto- optical Kerr effect for ultrafast magnetization dynamics in ferromagnetic thin films

作者：Razdolski I^*; Alekhin A; Martens U; Buerstel D; Diesing D; Muenzenberg M; Bovensiepen U; Melnikov A^*

来源：Journal of Physics: Condensed Matter , 2017, 29(17): 174002.

DOI：10.1088/1361-648X/aa63c6

• magnetization dynamics
• magneto-optical Kerr effect
• electronic transport
• hot electrons
• ultrafast demagnetization

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.

• 出版日期2017-5-4