“…1(b), it can already be seen by the dark rims around islands and substrate steps that the photon emission is significantly reduced when the STM tip is placed near a step edge. Such a reduced intensity at step edges has already been observed on other closely packed noble metal surfaces like Au(111) [22], Au(110) [23], Cu(111) [24], and Ag(111) [4,25,26], whereas on Au(110), enhanced emission was observed at step edges [5,27]. The effect was finally attributed by Hoffmann et al [5] to the local density of states (LDOS) at the step edge.…”