Presentation Information
[10p-PA3-36]Helicity-dependent optical spin-orbit torque in Co/Pt/MgO/Pt films
〇(M1)Rinki Ishibashi1,2, Nukui Koki1,2, Miki Soma2, Mizukami Shigemi2,3 (1.Tohoku Univ., 2.AIMR Tohoku Univ., 3.CSIS Tohoku Univ.)
Keywords:
opto-spintoronics,magnetization dynamics,Optical Spin-Orbit torque
Optical spin-orbit torque (OSOT) offers a promising route for ultrafast optical control of magnetization by generating spin angular momentum in heavy metals using circularly polarized light. To investigate the transport properties of light-induced spin angular momentum in Pt, we studied Co/Pt/MgO/Pt multilayers and reference Co/Pt films fabricated by magnetron sputtering. OSOT was evaluated using helicity-dependent time-resolved magneto-optical Kerr effect (TR-MOKE) measurements. The insertion of an MgO layer significantly reduced the helicity-induced torque, indicating suppression of spin-current injection from Pt into Co. These results suggest that MgO acts as an effective barrier for the transfer of light-induced spin angular momentum. Systematic dependence on Pt and MgO thickness provides insight into the generation, transport, and injection mechanisms of optically induced spin angular momentum in Pt, which is important for future opto-spintronic devices.