Illustration: Carin Cain

Figure 1: A fast way of reversing the magnetization $M$ is precessional switching (top), where a short field pulse $Hext$ is applied perpendicular to the magnetization. If the pulse is properly shaped, it can rotate the magnetization by 180°. The faster “linear” switching mode described by Vahaplar et al. (bottom) is driven by a short and intense circularly polarized laser pulse. Shortly after the pulse, the magnetization collapses due to heating. During the cooling, $M$ restores along the effective magnetic field $HIFE$ that is generated by the inverse Faraday effect.