  In Fe-based superconductors, electron doping is often realized by the
substitution of transition-metal atoms for Fe. In order to investigate how the
electronic structure of the parent compound is influenced by Zn substitution,
which supplies nominally four extra electrons per substituted atom but is
expected to induce the strongest impurity potential among the transition-metal
atoms, we have performed an angle-resolved photoemission spectroscopy
measurements on Ba(Fe_{1-x}Zn_x)_2As_2 (Zn-122). In Zn-122, the temperature
dependence of the resistivity shows a kink around T~135 K, indicating
antiferromagnetic order below the Neel temperature of T_N ~ 135 K. In fact,
folded Fermi surfaces (FSs) similar to those of the parent compound have been
observed below T_N. The hole and electron FS volumes are, therefore, different
from those expected from the rigid-band model. The results can be understood if
all the extra electrons occupy the Zn 3d state ~10 eV below the Fermi level and
do not participate in the formation of the FSs.
