[19p-P06-1~50] 10 Spintronics and Magnetics (Poster)

English Presentation

[19p-P06-22] Spin-current generation by ultrashort laser pulses in a heavy-metal/rare-earth iron garnet heterojunction

〇(M1)Shunsuke Takahashi¹, Yuga You², Kazuto Yamanoi², Yukio Nozaki², Takuya Satoh¹, Kihiro Yamada¹ (1.Tokyo Tech, 2.Keio Univ.)

Keywords:

femtosecond laser,spin current

The generation of spin currents is one of the central research topics in spintronics. Microwaves are commonly used for generation spin currents by resonantly exciting magnetization dynamics. On the other hand, in this research, we explored the potential of ultra-short optical pulses for spin-current generation. We irradiated femtosecond laser pulses, with a central wavelength of 800 nm and duration of 60 fs, to a Gd_3/2Yb_1/2BiFe_3/2O₁₂ single crystal covered with a heavy-metal electrode for generating spin currents. The spin currents were converted to electric currents in an adjacent electrode of heavy metal, such as Pt and Ta, through the inverse spin Hall effect. The electric-current waveforms were measured using an oscilloscope in conjunction with a trans-impedance amplifier.We observed electric-current waveforms of which polarity inverted depending on the polarities of the spin Hall effect and in-plane magnetic field . Furthermore, increasing the thickness of the electrode significantly reduces the peak amplitudes of the electric currents. These results suggest that the direct excitation of the hereto-interface plays a crucial role in the spin-current generation using femtosecond laser pulses.