Orbit-Transfer Torque Driven Field-Free Switching of Perpendicular Magnetization  

作　　者：Xing-Guo Ye Peng-Fei Zhu Wen-Zheng Xu Nianze Shang Kaihui Liu Zhi-Min Liao 叶兴国;朱鹏飞;徐文正;尚念泽;刘开辉;廖志敏(State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics,School of Physics,Peking University,Beijing 100871,China)

机构地区：[1]State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics,School of Physics,Peking University,Beijing 100871,China

出　　处：《Chinese Physics Letters》2022年第3期89-93,共5页中国物理快报（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.91964201 and 61825401)。

摘　　要：The reversal of perpendicular magnetization(PM)by electric control is crucial for high-density integration of low-power magnetic random-access memory.Although the spin-transfer torque and spin-orbit torque technologies have been used to switch the magnetization of a free layer with perpendicular magnetic anisotropy,the former has limited endurance because of the high current density directly through the junction,while the latter requires an external magnetic field or unconventional configuration to break the symmetry.Here we propose and realize the orbit-transfer torque(OTT),that is,exerting torque on the magnetization using the orbital magnetic moments,and thus demonstrate a new strategy for current-driven PM reversal without external magnetic field.The perpendicular polarization of orbital magnetic moments is generated by a direct current in a few-layer WTe_(2)due to the existence of nonzero Berry curvature dipole,and the polarization direction can be switched by changing the current polarity.Guided by this principle,we construct the WTe_(2)/Fe_(3)GeTe_(2)heterostructures to achieve the OTT driven field-free deterministic switching of PM.

关 键 词：POLARIZATION SWITCHED SWITCHING 

分 类 号：TP333[自动化与计算机技术—计算机系统结构]