A spin-pumping antiferromagnet Antiferromagnets have been used in spintronics mainly as a source of the so-called exchange bias. However, they hold promise for a much more active role given that their magnetization dynamics can in principle be much faster than those in ferromagnets. For this promise to materialize, antiferromagnets must learn the tricks that come naturally to ferromagnets. Vaidya et al. observed one such phenomenon called spin pumping (see the Perspective by Hoffmann). The researchers irradiated the antiferromagnet MnF ₂ with circularly polarized subterahertz light, causing the spins in this material to spring into action. These dynamics, in turn, caused the injection of spin current into a layer of platinum adjacent to MnF ₂ . Science , this issue p. 160 ; see also p. 135