One-dimensional Fe surface states confined by self-assembled carbon chains at the Fe(001) surface

A c (3 root 2 x root 2) reconstructed structure of the Fe(001) surface with self-assembled C zigzag chains has been recently observed experimentally. Using ab initio density-functional calculations, we address the effect of the C zigzag chains on the electronic structure of this surface. We find that the formation of the C chains produces one-dimensional surface states localized along the zigzag chains. These states are spin polarized and derive from pre-existing two-dimensional Fe d(3z2-r2)-like surface states of the clean Fe(001) surface. The simulation of scanning tunnel microscopy (STM) images allows us to assign the chainlike structure, observed in STM experiments, to the one-dimensional Fe surface states laterally confined within the C zigzag stripes.