  The electronic states of Au-induced atomic nanowires on Ge(001) (Au/Ge(001)
NWs) have been investigated by angle-resolved photoelectron spectroscopy with
linearly polarized light. We have found three electron pockets around
$\bar{J}\bar{K}$, where the Fermi surfaces are closed in a surface Brillouin
zone, indicating that the surface states of Au/Ge(001) NWs are two-dimensional
whereas the atomic structure is one-dimensional. The two-dimensional metallic
states exhibit remarkable suppression of the photoelectron intensity near a
Fermi energy. This suppression can be explained by the correlation and
localization effects in disordered metals, which is a deviation from a
Fermi-liquid model.
