Fig. 1: Single-pulse all-optical switching (SP-AOS) in Mn₂Ru_1.0Ga.

A uniformly-magnetized film with net magnetization M_net out of the plane (top) or into the plane (bottom) is irradiated by a single 800 nm pulse focused onto a ~100 µm spot. The pulse energy in a is 8.6 mJ cm⁻², which only exceeds the switching threshold in a small region at the center, where the fluence is highest. The 14.5 mJ cm⁻² pulse in b switches the whole irradiated area, whereas the 28.9 mJ cm⁻² pulse in c heats the film at the center of the spot above the Curie temperature, producing a fine multidomain pattern. The most intense pulses (43.4 mJ cm⁻²) lead to ablation of the film. The scale bar represents a length of 50 µm.