Lifetimes of Image-Potential States on Copper Surfaces
Lifetimes of Image-Potential States on Copper Surfaces
The lifetime of image states, related to the coupling of surface electronic states with the solid substrate, has been recently determined for quantum numbers $n\ensuremath{\le}6$ on Cu(100) by using time-resolved two-photon photoemission in combination with the coherent excitation of several states [U. H\"ofer et al., Science 277, 1480 (1997)]. We …