The orbital characters and kz dispersions of bands in iron-pnictide NaFeAs

The electronic structure and orbital characters of iron-pnictide NaFeAs have been studied by polarization dependent angle-resolved photoemission spectroscopy. Some of the bands are mixed with the orbitals of opposite symmetries, which could be interpreted by the hybridization among the bands. According to the photon energy dependent experiment, the kz dispersions of the bands that cross the Fermi energy are weak in both paramagnetic and spin density wave states. However, a band well below the Fermi level shows a kz dispersion of 41 meV, which mainly contains the dz2dz2 orbital.