News Report
Plasmon-Assisted Resonant Electron Tunneling in a Scanning Tunneling Microscope Junction
Nov 2018

This publication by Shuyi Liu, Martin Wolf, and Takashi Kumagai in Physical Review Lettersreports about plasmon-assisted resonant electron tunneling from a silver or gold tip to field emission resonances (FERs) of a Ag(111) surface induced by continuous wave (cw) laser excitation of a scanning tunneling microscope (STM) junction at visible wavelengths. As a hallmark of the plasmon-assisted resonant tunneling, a downshift of the first peak in the FER spectra by a fixed amount equal to the incident photon energy is observed. STM-induced luminescence measurement for the silver and gold tip reveals the clear correlation between the laser-induced change in the FER spectra and the plasmonic properties of the junction. These results clarify a novel resonant electron transfer mechanism in a plasmonic nanocavity.