Magnetization switching by spin-orbit torque in an antiferromagnet-ferromagnet bilayer system
Magnetization switching by spin-orbit torque in an antiferromagnet-ferromagnet bilayer system
复制标题
DOI：
10.1038/nmat4566
复制
发表时间：
2016-05-01
期刊：
影响因子：
41.2
通讯作者：
Ohno, Hideo
中科院分区：
文献类型：
--
作者：
Fukami, Shunsuke;Zhang, Chaoliang;Ohno, Hideo
自旋轨道力矩（SOT）诱导的磁化翻转显示出实现超快和可靠的自旋电子器件的希望。SOT的垂直磁化的双极切换是在与所施加的电流共线的面内磁场下实现的。到目前为止，研究的典型结构包括非磁性/铁磁体（NM/FM）双层，其中NM中的自旋霍尔效应负责开关。在这里，我们表明，反铁磁/铁磁（AFM/FM）双层系统也表现出SOT大到足以切换的FM的磁化。在这个材料系统中，由于交换偏置的AFM，我们观察到开关在没有施加的电场通过使用反铁磁PtMn和铁磁Co/Ni多层与垂直的易轴。此外，定制堆叠实现了类似忆阻器的行为，其中可以以模拟方式控制反向磁化的一部分。因此，AFM/FM系统是SOT设备的一个很有前途的构建模块，并提供了一个有吸引力的神经形态计算的途径。
Spin-orbit torque (SOT)-induced magnetization switching shows promise for realizing ultrafast and reliable spintronics devices. Bipolar switching of the perpendicular magnetization by the SOT is achieved under an in-plane magnetic field collinear with an applied current. Typical structures studied so far comprise a nonmagnet/ferromagnet (NM/FM) bilayer, where the spin Hall effect in the NM is responsible for the switching. Here we show that an antiferromagnet/ferromagnet (AFM/FM) bilayer system also exhibits a SOT large enough to switch the magnetization of the FM. In this material system, thanks to the exchange bias of the AFM, we observe the switching in the absence of an applied field by using an antiferromagnetic PtMn and ferromagnetic Co/Ni multilayer with a perpendicular easy axis. Furthermore, tailoring the stack achieves a memristor-like behaviour where a portion of the reversed magnetization can be controlled in an analogue manner. The AFM/FM system is thus a promising building block for SOT devices as well as providing an attractive pathway towards neuromorphic computing.