Surface-State Depopulation on Small Ag(111) Terraces

Abstract

The dependence of the local density of states near the Fermi energy E(F) on the width of terraces T is investigated by tunneling scanning spectroscopy on Ag(111) at 7 K. With decreasing T, the electronic density in the occupied surface state shifts monotonically towards E(F), leading to a depopulation at T=3.2 nm in quantitative agreement with a Fabry-Pérot model. Depopulation coincides with a switch from confinement by terrace modulation to step modulation.

Colloquium: Theory of quantum corrals and quantum mirages

“…The experiments abound with step edges (Bürgi et al, 1999b(Bürgi et al, , 1998Jeandupeux et al, 1999;Morgenstern et al, 2002), for example, even though one looks for regions as far away as possible from such defects to build corrals. The step edges affect the images, although not so much inside closed corrals, which have enough attenuation at the wall to prevent those paths which begin inside the corral, get out, hit an edge, and come back inside from having any important weight.…”

One-dimensional versus two-dimensional electronic states in vicinal surfaces

“…Tilting the (1 1 1) surface in the plane perpendicular to the [11 0] direction usually leads to a 1D array of equally spaced, monatomic, parallel steps of height h, separated by (1 1 1)-oriented terraces of width w = d cos α = h/ tan α. Consequently, macroscopic changes in α, e.g. between 15 • and 1 • , give rise to 1D superlattices, with nanoscopic lattice constant d between ∼10 and ∼100 Å, respectively.…”

“…In the past few years, a number of works have been devoted to the study of surface states in step arrays of Au and Cu surfaces vicinal to the (1 1 1) plane using angle-resolved photoemission spectroscopy (ARPES) [4]- [13] and scanning tunnelling microscopy (STM) [14,15]. Probably the most interesting observation concerns the change in the dimensionality of the surface state as one varies the superlattice constant d of the step array, as schematically depicted in figure 1.…”

Local potential fluctuation of topological surface states in Bi1.5Sb0.5Te1.7Se1.3 observed by Landau level spectroscopy

“…Such peaks indicate the presence of twodimensional surface states and their quantization in the field by the formation of LLs. [16][17][18]23 Other possibilities for the observed maxima in the spectra, such as the first resonance of standing waves in between the defects like in Morgenstern et al, 24 are excluded because the inter-defect spacing is much smaller than the wavelength of the electrons.…”