Edge state and terrace state for Cu on W(331) and W(110)

Abstract

The surface electronic structure of Cu on stepped and flat W(110) is determined with inverse photoemission. An intense, Cu-induced surface state is found at 0.6 eV above the Fermi level on W(110). It is located in the ${\mathrm{\Sigma }}_1$ band gap. On the stepped W(331) surface there is a similar state at 0.7 eV. This terrace state shifts down to 0.3 eV when the coverage of Cu is reduced such that only a single row of Cu atoms remains at a step edge.