0000000000222142
AUTHOR
S.-j. Noh
Spin orbit torque switching in Ta/CoFeB/MgO without longitudinal fields
Intense investigations are carried out on novel magnetic materials systems with perpendicular magnetic anisotropy (PMA), where new spin-orbit effects occur due to structural inversion asymmetry (SIA). So called spin-orbit torques (SOTs), have been observed for the first time in PMA nano-structures with SIA, when an electric current is injected [1-3], leading to ultra-efficient current-induced domain wall motion and current-induced magnetization switching [2,3].
Spin-orbit torque-driven magnetization switching and thermal effects studied in Ta\CoFeB\MgO nanowires
We demonstrate magnetization switching in out-of-plane magnetized Ta\CoFeB\MgO nanowires by current pulse injection along the nanowires, both with and without a constant and uniform magnetic field collinear to the current direction. We deduce that an effective torque arising from spin-orbit effects in the multilayer drives the switching mechanism. While the generation of a component of the magnetization along the current direction is crucial for the switching to occur, we observe that even without a longitudinal field thermally generated magnetization fluctuations can lead to switching. Analysis using a generalized N\'eel-Brown model enables key parameters of the thermally induced spin-orbi…