Fig. 1. Schematic of the time- and spin-resolved XUV photoemission spectroscopy experiment and the potential response of the electronic and spin systems to laser-induced demagnetization.

(A) The thin, in-plane-magnetized Co film (30 ML) is excited with near-infrared (NIR) laser pulses (74 ± 1 fs, 1.6 eV) that induce demagnetization. The evolution of the band structure is measured via spin- and time-resolved photoemission using XUV pulses (33 ± 7 fs, 22 eV) from high-harmonic generation (HHG). (B) Exchange split density of states for a 3d ferromagnet (left). Reduced magnetization in the Stoner-like picture via a potential collapse of the exchange splitting (middle) and in the localized spin picture via band mirroring (right).