講演情報
[8p-E207-13]Influence of C60 layer in spin transport investigated by ultrafast spin-to-charge conversion in organic spintronic multilayers
〇Fumi Nishino1, Takuto Nakamura2, Eriko Fukasawa2, Akira Yasui3, Koji Horiba1, Shin-ichi Kimura2, Takeshi Suzuki2 (1.QST, 2.Univ. of Osaka, 3.JASRI)
キーワード：
organic-inorganic interface、spin-to-charge conversion
Spin-to-charge conversion (SCC) based on the Rashba–Edelstein effects is a key technology in spintronics. SCC has generally been studied using multilayer structures including a nonmagnetic layer for spin transport. To improve spin transport efficiency in such systems, organic molecules composed of light elements have attracted considerable attention owing to their potentially long spin diffusion lengths arising from weak spin–orbit coupling. However, the structural complexity of molecule–metal interfaces makes it difficult to clarify spin transport mechanisms and has limited their application to SCC devices.
In this study, we investigate spin transport through an organic molecular layer by introducing a highly oriented C60 film into the Rashba-type SCC system Bi/Ag/Fe. Multilayer samples consisting of Fe (2 nm), Ag (2 nm), and Bi (2 nm) were fabricated on MgO(001), and high-quality epitaxial C60 films were grown on Fe/MgO(001). Interface structures and chemical bonding states were characterized by reflection high-energy electron diffraction and hard X-ray photoelectron spectroscopy. SCC was evaluated through THz emission generated by ultrafast spin-to-charge conversion induced by femtosecond laser excitation.Clear THz emission with magnetic-field-dependent phase reversal was observed from Bi/Ag/Fe, confirming Rashba-mediated SCC. THz signals were also detected after insertion of the C60 layer, indicating spin transport through C60. The relationship between SCC efficiency, interface structure, and C60 thickness will be discussed.
In this study, we investigate spin transport through an organic molecular layer by introducing a highly oriented C60 film into the Rashba-type SCC system Bi/Ag/Fe. Multilayer samples consisting of Fe (2 nm), Ag (2 nm), and Bi (2 nm) were fabricated on MgO(001), and high-quality epitaxial C60 films were grown on Fe/MgO(001). Interface structures and chemical bonding states were characterized by reflection high-energy electron diffraction and hard X-ray photoelectron spectroscopy. SCC was evaluated through THz emission generated by ultrafast spin-to-charge conversion induced by femtosecond laser excitation.Clear THz emission with magnetic-field-dependent phase reversal was observed from Bi/Ag/Fe, confirming Rashba-mediated SCC. THz signals were also detected after insertion of the C60 layer, indicating spin transport through C60. The relationship between SCC efficiency, interface structure, and C60 thickness will be discussed.