Surface electronic structure of ferromagnetic Fe(001)

A thorough investigation of the surface electronic structure of ferromagnetic Fe(100) films, epitaxially grown on single-crystal W(100), has been conducted using spin- and angle-resolved photoemission combined with state-of-the-art density-functional theory slab computations. The dispersion of the surface emission close to the Fermi level has been assessed quantitatively. The experimental results are in a good agreement with the calculations and, in particular, the presence of a minority surface state with dxz+yz character along the ΓX high-symmetry direction is unambiguously established. Additionally, the calculations predict the existence of a different unoccupied surface state localized at Γ. The existence of the related minority interface resonance near the Fermi edge and outside of the surface-Brillouin-zone center Γ is believed to control the tunneling magnetoresistance in Fe/MgO/Fe(001) for very thin MgO spacers thus our results serve as indirect confirmation to these predictions.