Spin-polarized surface states close to adatoms on Cu(111)

We present a theoretical study of surface states close to 3d transition-metal adatoms (Cr, Mn, Fe, Co, Ni, and Cu) on a Cu(111) surface in terms of an embedding technique using the fully relativistic Korringa-Kohn-Rostoker method. For each of the adatoms we found resonances in the s-like states to be attributed to a localization of the surface states in the presence of an impurity. We studied the change of the s-like densities of states in the vicinity of the surface-state band edge due to scattering effects mediated via the adatom's d orbitals. The results obtained clearly show that a magnetic impurity causes spin polarization of the surface states. In particular, the long-range oscillations of the spin-polarized s-like density of states around an Fe adatom are demonstrated.