Estimating the range of influence of point defects on Cu(110) surface states

By utilising Reflection Anisotropy Spectroscopy (RAS) and Scanning Tunnelling Microscopy (STM) measurements of the ion bombarded Cu(110) surface at low temperatures, we have developed a simple methodology for estimating the surface area over which a single atomic defect locally influences surface states such that the contribution to the intensity of the 2.1 eV RAS peak involving these states is destroyed. We estimate this area to be approximately equal to that of a circle with a radius of 0.75 nm: an area in the surface plane equivalent to that of around 19 unit cells. By employing STM to accurately determine the coverage and spatial distribution of irradiation-induced defects, we are able to develop a coherent analytical approach to model this system.