Abstract
We report on long-range interactions between adsorbates on metal surfaces with a surface state. A comparison of three adsorbate/substrate systems [Cu/Cu(111), Co/Cu(111), and Co/Ag(111)] suggests the general existence of such interactions and shows up common characteristics. In all cases, the interaction energy manifests itself up to a distance of 60 Å, decays as and oscillates with a period of Our data are in excellent agreement with theory and establish the link between the spatial variation of the interaction energy and the adsorbate scattering properties. We demonstrate that the long-range interactions stabilize an ordered two-dimensional (2D) gas of adsorbates and thus create states of dilute 2D matter.
- Received 2 November 2001
DOI:https://doi.org/10.1103/PhysRevB.65.115420
©2002 American Physical Society