Interplay between indirect interaction and charge-density wave in Pb-adsorbedIn(4×1)−Si(111)

Abstract

The response of the electronic structure of the quasi-one-dimensional $\mathrm{In}(4\ifmmode\times\else\texttimes\fi{}1)\text{\ensuremath{-}}\mathrm{Si}(111)$ surface to the adsorption of Pb atoms is investigated by scanning tunneling microscopy and first-principles calculations. Instead of a period of even multiples of the underlying In lattice spacing $a$ along the In wire, as favored by the low temperature charge-density wave (CDW) modulation, the Pb adatoms are frequently found to occupy the odd adsorption sites separated by a distance $3a$ or $5a$. These observations indicate a strong antiphase interference between the indirect interaction of adsorbed Pb atoms and the intrinsic CDW of the $\mathrm{In}(4\ifmmode\times\else\texttimes\fi{}1)\text{\ensuremath{-}}\mathrm{Si}(111)$ surface.