  Recent photoemission experiments on the Si(553)-Au reconstruction show a
one-dimensional band with a peculiar ~1/4 filling. This band could provide an
opportunity for observing large spin-charge separation if electron-electron
interactions could be increased. To this end, it is necessary to understand in
detail the origin of this surface band. A first step is the determination of
the structure of the reconstruction. We present here a study of several
structural models using first-principles density functional calculations. Our
models are based on a plausible analogy with the similar and better known
Si(557)-Au surface, and compared against the sole structure proposed to date
for the Si(553)-Au system [Crain JN et al., 2004 Phys. Rev. B 69 125401 ].
Results for the energetics and the band structures are given. Lines for the
future investigation are also sketched.
