Experimental demonstration of voltage-gated spin-orbit torque switching in an antiferromagnet/ferromagnet structure
Weixiang Li, Shouzhong Peng, Jiaqi Lu, Hao Wu, Xiang Li, Danrong Xiong, Yan Zhang, Youguang Zhang, Kang L. Wang, Weisheng Zhao
Abstract
Efficient manipulation of magnetization is crucial for magnetic random-access memory (MRAM). Here we experimentally demonstrate spin-orbit-torque-driven (SOT-driven) magnetization switching of perpendicularly magnetized IrMn/CoFeB/MgO structures with the assist of a gate voltage. It is found that with the gate voltage changing from \ensuremath{-}0.6 to 0.6 V, the SOT critical switching current density ${J}_{c}$ is reduced by 59%. Furthermore, the mechanism of voltage-induced ${J}_{c}$ reduction is explored. We find that the dampinglike torque decreases with positive voltage, while the fieldlike torque shows a weak voltage dependence, which demonstrates that the voltage control of spin-orbit torque (VCSOT) effect has no positive effect on the reduction of ${J}_{c}$. In addition, a significant decrease of anisotropy energy is observed when a positive voltage is applied. These results indicate that both VCSOT effect and voltage control of magnetic anisotropy (VCMA) effect exist in voltage-gated SOT switching, while the VCMA effect plays a main role in reduction of ${J}_{c}$. This work shows low-power magnetization switching and helps to understand the mechanism of voltage-gated SOT switching.