title: Step-lattice-induced band-gap opening at the fermi level.
abstract: The interaction of the Shockley surface state with the step lattice of vicinal Cu(111) leads to the formation of an electronic superlattice state. On Cu(443), where the average terrace length forms a "shape resonance" with the Fermi wavelength, we find a step-lattice-induced band-gap opening at the Fermi level. A gap magnitude >200 meV is inferred from high resolution photoemission experiments and line shape analysis. The corresponding energy gain with respect to a gapless case is approximately 11 meV/unit cell, and is a substantial contribution to the stabilization of the step lattice.
authors.affiliation: Physikinstitut der Universität Zürich, Winterthurerstrasse 190, CH-8057 Zürich, Switzerland. baumberger@stanford.edu
authors.forename: F
authors.initials: F
authors.lastname: Baumberger
authors.forename: M
authors.initials: M
authors.lastname: Hengsberger
authors.forename: M
authors.initials: M
authors.lastname: Muntwiler
authors.forename: M
authors.initials: M
authors.lastname: Shi
authors.forename: J
authors.initials: J
authors.lastname: Krempasky
authors.forename: L
authors.initials: L
authors.lastname: Patthey
authors.forename: J
authors.initials: J
authors.lastname: Osterwalder
authors.forename: T
authors.initials: T
authors.lastname: Greber