Spin-resolved electronic structure of 3d transition metals during ultrafast demagnetization

In this work we follow up on the pioneering work of Jean-Yves Bigot and Eric Beaurepaire about disentangling microscopic properties in femtosecond magnetization dynamics such as spin and orbital momenta (Boeglin et al., 2010). To this end, we utilize spin-resolved photoemission to distinguish spin polarization and exchange splitting as essential magnetic properties in the ultrafast demagnetization of thin Fe films on W(1 1 0). In laser photoemission (h nu(Probe) = 6.2 eV) we find an ultrafast breakdown of the spin polarization after exciting the system with 70-fs pump laser-pulses at h nu(p)(um)(p) = 1.6 eV. Measuring a minority-spin surface resonance close to the Fermi level at 0.12 angstrom(-1) in (Gamma) over bar - (H) over bar direction, we establish a band mirroring effect similar to the ones observed in Eich et al. (2017) and Gort et al. (2018).