Spin–orbit torques (SOTs) in multilayers of ferromagnetic (FM) and non-magnetic (NM) metals can manipulate the magnetization of the FM layer efficiently. This is employed, for example, in non-volatile magnetic memories for energy-efficient mobile electronics^1,2 and spin torque nano-oscillators^3,4,5,6,7 for neuromorphic computing⁸. Recently, spin torque nano-oscillators also found use in microwave-assisted magnetic recording, which enables ultrahigh-capacity hard disk drives⁹. Most SOT devices employ spin Hall^10,11 and Rashba¹² effects, which originate from spin–orbit coupling within the NM layer and at the FM/NM interfaces, respectively. Recently, SOTs generated by the anomalous Hall effect in FM/NM/FM multilayers were predicted¹³ and experimentally realized¹⁴. The control of SOTs through crystal symmetry was demonstrated as well¹⁵. Understanding all the types of SOTs that can arise in magnetic multilayers is needed for a formulation of a comprehensive SOT theory and for engineering practical SOT devices. Here we show that a spin-polarized electric current known to give rise to anisotropic magnetoresistance (AMR) and the planar Hall effect (PHE) in a FM¹⁶ can additionally generate large antidamping SOTs with an unusual angular symmetry in NM₁/FM/NM₂ multilayers. This effect can be described by a recently proposed magnonic mechanism¹⁷. Our measurements reveal that this torque can be large in multilayers in which both spin Hall and Rashba torques are negligible. Furthermore, we demonstrate the operation of a spin torque nano-oscillator driven by this SOT. These findings significantly expand the class of materials that exhibit giant SOTs.

铁磁（FM）和非磁（NM）金属多层中的自旋轨道转矩（SOT）可以有效地控制FM层的磁化。例如，在用于节能移动电子产品^1,2的非易失性磁性存储器中以及用于神经形态计算^8的自旋扭矩纳米振荡器^{3,4,5,6,7中采用}了这种方法。最近，自旋扭矩纳米振荡器也被用于微波辅助磁记录中，这使得超高容量硬盘驱动器^{9成为可能}。大多数SOT设备采用自旋Hall ^10,11和Rashba ¹²效应分别来自NM层内和FM / NM界面上的自旋轨道耦合。最近，由FM / NM / FM多层中的异常霍尔效应产生的SOT被预测¹³并通过实验实现¹⁴。通过晶体对称性控制SOTs也得到了证实¹⁵。了解全面的SOT理论和工程实用SOT器件需要了解磁性多层中可能出现的所有SOT类型。在这里，我们表明，自旋极化电流已知引起各向异性磁阻（AMR）和在FM平面霍尔效应（PHE）¹⁶可以附加地产生在NM用一个不寻常的角度对称大antidamping SOTS ₁/ FM / NM ₂多层。这种效果可以通过最近提出的强磁机构¹⁷来描述。我们的测量结果表明，在自旋霍尔和Rashba转矩均可以忽略的多层结构中，该转矩可能很大。此外，我们演示了由该SOT驱动的自旋扭矩纳米振荡器的操作。这些发现极大地扩展了展现巨型SOT的材料类别。