Photon emission from nanostructures in an STM

Using an STM we have created and investigated individual small particles with apparent lateral dimensions between 10 Å and 250 Å on metal single-crystal surfaces and metallic films. These particles are clearly observed in simultaneous measurements of STM topographs and emission of photons from the tunneling gap. The particles give rise to order-of-magnitude variations in photon intensity with subnanometer lateral resolution. We interpret the observed photon emission characteristics in terms of inelastic tunneling excitation of tip-induced, localized plasmon modes. © 1993.