Antiferromagnets (AFMs) have the potential to push spintronic devices from a static condition or gigahertz frequency range to the terahertz range for the sake of high-speed processing. However, the insensitivity of AFMs to magnetic fields makes the manipulation of spin currents difficult. The ultrafast generation of the spin current in ferromagnet/heavy-metal (HM) structures has received a lot of attention in recent years, but whether a similar scenario can be observed in an AFM/HM system is still unknown. Here, we show the optical generation of ultrafast spin current in an AFM/HM heterostructure at zero external magnetic field and at room temperature by detecting the associated terahertz emission. We believe that this is a common phenomenon in antiferromagnets with strong nonlinear optical effects. Our results open an avenue of fundamental research into antiferromagnetism and a route to AFM spintronic devices.

反铁磁体（AFM）有可能将自旋电子器件从静态或千兆赫兹频率范围推至太赫兹范围，以进行高速处理。但是，原子力显微镜对磁场的不敏感性使自旋电流难以控制。近年来，铁磁体/重金属（HM）结构中自旋电流的超快产生引起了很多关注，但是在AFM / HM系统中是否可以观察到类似情况仍然未知。在这里，我们通过检测相关的太赫兹发射，在零外部磁场和室温下显示了AFM / HM异质结构中超快自旋电流的光学生成。我们认为，这是具有强非线性光学效应的反铁磁体中的常见现象。