Layer-Specific Measurement of Ultrafast Spin Dynamics in GdFeCo Double Layer with Dielectric Interlayer

抄録

  In recent years, the importance of understanding dynamic properties of magnetic materials is increasing. For designing dynamic responses in ultrafast optical control applications to spintronic devices, clarifying intra- and inter-layer energy dissipation process and spin dynamics in multilayered systems is an important issue. In this study, we investigated layer-specific measurement of ultrashort laser-induced ultrafast demagnetization and precession in magnetically and electrically decoupled GdFeCo double-layered film by all-optical pump-probe method. After laser excitation, demagnetization level of the first magnetic layer located at pump light incident side is about 5 times as large as another layer within ～ps range. Furthermore, from a time evolution of Faraday rotation in recovering processes, it is found that lattice temperature of each magnetic layer equilibrates at ～400 ps. Finally, independent precessional oscillation of each magnetic layer is clearly observed.