Coupling of Surface Electronic States through the W {001} Phase Transition

Abstract

Angle-resolved photoemission spectra obtained from the W{001}-(1 × 1) structure are compared with spectra from the cooled $(\sqrt{2}\times \sqrt{2})R45$° surface structure, providing the first experimental evidence for the coupling of surface states at the Fermi energy on formation of the latter phase. Calculations of the surface density of states are in good agreement with experiment. A prominent new feature observed from the low-temperature phase (at the 1 × 1 $\overline{M}$ point) is attributable to an umklapp process.