Antiferromagnets are magnetically ordered materials without a macroscopic magnetization. As a result, they could be of use in the development of memory devices because data cannot be erased by external magnetic fields. However, this also makes it difficult to electrically control their magnetic order (Néel vector). Here, we show that pillars of antiferromagnetic PtMn, which are grown on a heavy-metal layer and have diameters down to 800 nm, can be reversibly switched between different magnetic states by electric currents. The devices are based on materials that are typically used in the magnetic memory industry, and we observe switching down to a current density of ~2 MA cm⁻². Furthermore, by varying the amplitude of the writing current, multilevel memory characteristics can be achieved. Micromagnetic simulations suggest that the different magnetic states may consist of domains separated by domain walls with vortex and anti-vortex textures that move in response to current, modifying the average Néel vector.

反铁磁体是没有宏观磁化的磁性排序材料。结果，它们可能在存储设备的开发中有用，因为数据不能被外部磁场擦除。然而，这也使得难以电控制它们的磁阶（Néel矢量）。在此，我们显示出，在重金属层上生长且直径低至800 nm的反铁磁PtMn的支柱可以通过电流在不同的磁性状态之间可逆地切换。这些器件基于通常在磁存储行业中使用的材料，并且我们观察到切换到〜2 MA cm ^-2的电流密度。此外，通过改变写入电流的幅度，可以实现多级存储特性。微磁模拟表明，不同的磁态可能由磁畴壁分隔开的磁畴组成，该磁畴壁具有涡流和反涡流纹理，这些纹理会响应电流而移动，从而改变平均Néel向量。