  We have performed an angle-resolved photoemission spectroscopy (ARPES) study
of the undoped and electron-doped iron pnictides BaFe2\_{-x}CoxAs2 (Ba122)
(x=0, 0.14) and studied the Fermi surfaces (FSs) and band dispersions near the
Fermi level. The FS sheets we observed are consistent with the shrinkage of the
hole-like pockets around the Brillouin Zone (BZ) center and the expansion of
the electron pockets around the BZ corner in the electron-doped compound as
compared to the undoped parent compound. Band dispersions and FSs around the BZ
center strongly depend on the photon energy, indicating the three-dimensional
(3D) electronic structure. This observation suggests that the
antiferromagnetism and superconductivity in the pnictides may have to be
considered including the orbital-dependent 3D electronic structure, where FS
nesting is not necessarily strong.
