Electron-plasmon and electron-electron interactions at a single atom contact

Phys Rev Lett. 2009 Feb 6;102(5):057401. doi: 10.1103/PhysRevLett.102.057401. Epub 2009 Feb 3.


The transition from tunneling to contact is investigated by detecting light emitted from Au(111) in a scanning tunneling microscope. Optical spectra reflect single and multielectron processes and their distinct evolutions as a single-atom contact is formed. The experimental data are analyzed in terms of plasmon excitation and hot-hole processes.