  We explore the possibility of ultrafast, coherent all-optical magnetization
switching in antiferromagnets by studying the action of the inverse Faraday
effect in CrPt, an easy-plane antiferromagnet. Using a combination of density
functional theory and atomistic spin dynamics simulations, we show how a
circularly polarized laser pulse can switch the order parameter of the
antiferromagnet within a few hundred femtoseconds. This nonthermal switching
takes place on an elliptical path, driven by the staggered magnetic moments
induced by the inverse Faraday effect and leading to reliable switching between
two perpendicular magnetic states.
