Department of Electrical and Computer Engineering , National University of Singapore , 117576 Singapore.
Nano Lett. 2018 Aug 8;18(8):4669-4674. doi: 10.1021/acs.nanolett.8b00773. Epub 2018 Jul 3.
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.
自旋轨道扭矩利用自旋轨道耦合产生的自旋流，为具有垂直各向异性的磁化强度的电切换提供了一种新方法。然而，为了实现具有全电操作的实际自旋轨道扭矩器件，需要外部磁场来实现确定性切换，这是一个障碍。在这里，我们通过利用具有垂直各向异性的反缺口微丝中的畴壁运动来报告无场自旋轨道扭矩切换，该微丝具有由畴壁表面张力稳定的多畴状态。自旋轨道扭矩、Dzyaloshinskii-Moriya 相互作用以及畴壁表面张力诱导的几何钉扎的结合允许对畴壁进行确定性控制，并提供了一种实现无场自旋轨道扭矩切换的新方法。我们的工作证明了可以在三端磁存储器中轻易采用的垂直存储单元的概念验证。
