The interplay of local electron correlations and ultrafast spin dynamics in fcc Ni

The complex electronic structure of metallic ferromagnets is determined by a balance between exchange interaction, electron hopping leading to band formation, and local Coulomb repulsion. By combining high energy temporal resolution in femtosecond time-resolved X-ray absorption spectroscopy with ab initio time-dependent density functional theory we analyze the fcc Ni on time scale these interactions pump-probe experiment. We distinguish transient broadening shifts spectra, which demonstrate be captured repopulation respectively correlation-induced modifications structure, requiring take interaction into account.