  The electronic structure of Si(110)"16 x 2" double-domain, single-domain and
1 x 1 surfaces have been investigated using spin- and angle-resolved
photoemission at sample temperatures of 77 K and 300 K. Angle-resolved
photoemission was conducted using horizontally- and vertically-polarised 60 eV
and 80 eV photons. Band-dispersion maps revealed four surface states ($S_1$ to
$S_4$) which were assigned to silicon dangling bonds on the basis of measured
binding energies and photoemission intensity changes between horizontal and
vertical light polarisations. Three surface states ($S_1$, $S_2$ and $S_4$),
observed in the Si(110)"16 x 2" reconstruction, were assigned to Si adatoms and
Si atoms present at the edges of the corrugated terrace structure. Only one of
the four surface states, $S_3$, was observed in both the Si(110)"16 x 2" and 1
x 1 band maps and consequently attributed to the pervasive Si zigzag chains
that are components of both the Si(110)"16 x 2" and 1 x 1 surfaces. A state in
the bulk-band region was attributed to an in-plane bond. All data were
consistent with the adatom-buckling model of the Si(110)"16 x 2" surface.
Whilst room temperature measurements of $P_y$ and $P_z$ were statistically
compatible with zero, $P_x$ measurements of the enantiomorphic A-type and
B-type Si(110)"16 x 2" surfaces gave small average polarisations of around
1.5\% that were opposite in sign. Further measurements at 77 K on A-type
Si(110)"16 x 2" surface gave a smaller value of +0.3\%. An upper limit of
$\sim1\%$ may thus be taken for the longitudinal polarisation.
