General features of photoinduced spin dynamics in ferromagnetic and ferrimagnetic compounds.
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.
Ogasawara
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Correlated Electron Research Center (CERC), National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba 305-8562, Japan.
Ohgushi
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K
Tomioka
Y
Y
Takahashi
K S
KS
Okamoto
H
H
Kawasaki
M
M
Tokura
Y
Y