Deviation from Fermi-liquid behavior in two-dimensional surface states   of Au-induced nanowires on Ge(001) by correlation and localization
  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. 
K. Yaji, R. Yukawa, S. Kim, Y. Ohtsubo, P. Le F\`evre, F. Bertran, A.   Taleb-Ibrahimi, I. Matsuda, K. Nakatsuji, F. Komori
cond-mat.mes-hall