Spin–orbit torques, which utilize spin currents arising from the spin–orbit coupling, offer a novel method for the electrical switching of the magnetization with perpendicular anisotropy. However, the necessity of an external magnetic field to achieve deterministic switching is an obstacle for realizing practical spin–orbit torque devices with all-electric operation. Here, we report field-free spin–orbit torque switching by exploiting the domain-wall motion in an anti-notched microwire with perpendicular anisotropy, which exhibits multidomain states stabilized by the domain-wall surface tension. The combination of spin–orbit torque, Dzyaloshinskii–Moriya interactions, and domain-wall surface-tension-induced geometrical pinning allows the deterministic control of the domain wall and offers a novel method to achieve a field-free spin–orbit torque switching. Our work demonstrates the proof of concept of a perpendicular memory cell that can be readily adopted in three-terminal magnetic memory.

中文翻译：

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几何畴壁固定的无场自旋-轨道转矩切换

利用利用自旋轨道耦合产生的自旋电流的自旋轨道转矩，提供了一种具有垂直各向异性的磁化电开关的新方法。然而，必须要有外部磁场来实现确定性的转换，这是实现具有全电操作的实际自旋轨道扭矩装置的一个障碍。在这里，我们通过利用具有垂直各向异性的反缺口微线中的畴壁运动报告了无场自旋轨道转矩切换，该微线具有通过畴壁表面张力稳定的多畴状态。自旋轨道转矩，Dzyaloshinskii-Moriya相互作用的结合，磁畴壁表面张力引起的几何钉扎可以确定性地控制磁畴壁，并提供一种新颖的方法来实现无场自旋轨道转矩切换。我们的工作证明了垂直存储单元的概念证明，该存储单元可以很容易地应用于三端磁存储中。