1] Department of Electrical Engineering, University of California, Los Angeles, California 90095, USA [2].
Department of Electrical Engineering, University of California, Los Angeles, California 90095, USA.
Nat Nanotechnol. 2014 Jul;9(7):548-54. doi: 10.1038/nnano.2014.94. Epub 2014 May 11.
Magnetization switching by current-induced spin-orbit torques is of great interest due to its potential applications in ultralow-power memory and logic devices. The switching of ferromagnets with perpendicular magnetization is of particular technological relevance. However, in such materials, the presence of an in-plane external magnetic field is typically required to assist spin-orbit torque-driven switching and this is an obstacle for practical applications. Here, we report the switching of out-of-plane magnetized Ta/Co(20)Fe(60)B(20)/TaO(x) structures by spin-orbit torques driven by in-plane currents, without the need for any external magnetic fields. This is achieved by introducing a lateral structural asymmetry into our devices, which gives rise to a new field-like spin-orbit torque when in-plane current flows in these structures. The direction of the current-induced effective field corresponding to this field-like spin-orbit torque is out-of-plane, facilitating the switching of perpendicular magnets.
电流诱导的自旋轨道扭矩的磁化开关因其在超低功耗存储器和逻辑器件中的潜在应用而备受关注。具有垂直磁化的铁磁体的开关具有特殊的技术相关性。然而，在这种材料中，通常需要存在面内外部磁场来辅助自旋轨道扭矩驱动的切换，这对于实际应用来说是一个障碍。在这里，我们报告了通过平面电流驱动的自旋轨道扭矩实现了 Ta/Co(20)Fe(60)B(20)/TaO(x)结构的面外磁化的切换，而无需任何外部磁场。这是通过在我们的器件中引入横向结构不对称性来实现的，当平面电流在这些结构中流动时，会产生一种新的场型自旋轨道扭矩。与这种场型自旋轨道扭矩对应的电流感应有效场的方向是面外的，有利于垂直磁体的切换。
