Si(110)5x2-Au: A metallic chain structure

The Si(110) surface is found to form a stable 5 x 2 reconstruction upon incorporation of about eight gold atoms per (110)-5 x 2 unit cell. By means of scanning-tunneling microscopy we observe an array of one-dimensional chains with an internal double-row structure. Angle-resolved photoemission reveals that this reconstruction forms a metallic band which is split at the Fermi level.