Electronic interchain interactions of the Cu(1 1 0)(2 × 1)O surface––an angle-resolved photoemission study

Using angle-resolved photoemission at <f>ℎω=21.2</f> eV we have measured the electronic energy band dispersion perpendicular to the Cu–O chains, i.e. along the <f><ovl type="bar" STYLE="S">Γ</ovl></f>–<f><ovl type="bar" STYLE="S">X</ovl></f> and <f><ovl type="bar" STYLE="S">Y</ovl></f>–<f><ovl type="bar" STYLE="S">S</ovl></f> directions of the surface Brillouin zone. Our work treats exclusively the occupied antibonding states observed at binding energies between <f>EF</f> and the upper edge of the Cu d-bands. We studied both the fully oxygen-covered surface (0.5 ML coverage) and the striped surface (global coverage <0.5 ML), where alternating Cu(1 1 0) and (2 × 1)O domains form a quasi-1D nanograting. In addition we analyze an umklapp-process of bulk substrate emission. It is induced by the (2 × 1) lattice of the adsorbate and needs to be distinguished from oxygen-derived electronic properties. We compare our results with earlier experimental studies and with available surface band structure calculations. [Copyright &y& Elsevier]