| Budget Amount *help |
¥4,940,000 (Direct Cost: ¥3,800,000、Indirect Cost: ¥1,140,000)
Fiscal Year 2014: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
Fiscal Year 2013: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
Fiscal Year 2012: ¥2,340,000 (Direct Cost: ¥1,800,000、Indirect Cost: ¥540,000)
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| Outline of Final Research Achievements |
The laser-induced ultrafast spin dynamics have been investigated by time-resolved pump-probe and Faraday rotation spectroscopies in ferromagnetic EuO thin films.
We demonstrate that the laser beam can enhance the magnetization on an ultrafast time scale. The decays time for the magnetization enhancement is about 1 nanosecond. In its temperature dependence, there is a maximum slightly below the Curie temperature associated with this dynamical enhancement of magnetization.
It also dominates the demagnetization counterpart at 55 K. It is attributed that this transient collective ordering to the enhancement of the f-d exchange interaction as a result of photoexcitation. We also observed that the circularly polarized light can control the magnetization precession at 10 K. This takes place within the 100-fs duration of a single laser pulse, through combined contribution from two nonthermal photomagnetic effects, i.e., enhancement of the magnetization and an inverse Faraday effect.
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