Spin-wave excitations of magnetic moments (or magnons) can transport spin angular momentum in insulating magnetic materials. This property distinguishes magnonic devices from traditional electronics, where power consumption results from electrons’ movement. Recently, magnon torques have been used to switch perpendicular magnetization in the presence of an external magnetic field. Here we present a material system composed of WTe₂/antiferromagnetic insulator NiO/ferromagnet CoFeB heterostructures that allows magnetic field-free switching of the perpendicular magnetization. The magnon currents, with a spin polarization canting of −8.5° relative to the sample plane, traverse the 25-nm-thick polycrystalline NiO layer while preserving their original polarization direction, subsequently exerting an out-of-plane anti-damping magnon torque on the ferromagnetic layer. Using this mechanism, we achieve a 190-fold reduction in power consumption in PtTe₂/WTe₂/NiO/CoFeB heterostructures compared to Bi₂Te₃/NiO/CoFeB control samples, which only exhibit in-plane magnon torques. Our field-free demonstration contributes to the realization of all-electric, low-power, perpendicular magnetization switching devices.

磁矩（或磁振子）的自旋波激发可以在绝缘磁性材料中传输自旋角动量。这一特性将磁振器件与传统电子设备区分开来，传统电子设备的功耗来自于电子的运动。最近，磁振子扭矩已被用来在存在外部磁场的情况下切换垂直磁化。在这里，我们提出了一种由WTe ₂ /反铁磁绝缘体NiO/铁磁体CoFeB异质结构组成的材料系统，该系统允许垂直磁化强度的无磁场切换。磁振子电流相对于样品平面的自旋极化倾斜为-8.5°，穿过25 nm厚的多晶NiO层，同时保留其原始偏振方向，随后对样品施加面外抗阻尼磁振子扭矩。铁磁层。利用这种机制，与仅表现出面内磁振子扭矩的 Bi ₂ Te ₃ /NiO/CoFeB 对照样品相比，我们在 PtTe ₂ /WTe ₂ /NiO/CoFeB 异质结构中实现了 190 倍的功耗降低。我们的无场演示有助于实现全电动、低功耗、垂直磁化开关器件。