Surface quantum well state at the striped Cu(1 1 0)(2 × 1)O surface studied by angle resolved photoemission spectroscopy

We have performed an angle resolved photoemission spectroscopy with high energy and high momentum resolutions and have observed the k dependent energy dispersion curves of the striped Cu(1 1 0)(2 × 1)O surface. It is found that the Shockley surface state electron is confined in the clean surface along the perpendicular direction to the stripes and forms a quantum well state (QWS). It has also been clearly observed that an electron of Cu-O antibonding state is confined within the oxygen covered surface.