Physical properties often boil down to the arrangement of electrons within a solid, which means that mapping the electronic structure is a powerful way of classifying and understanding a wide range of materials. By applying ultrashort laser pulses with 22 eV photon energy from a novel 500 kHz extreme-ultraviolet light source to chains of indium atoms on a silicon surface, we are able to produce a detailed map of electronic states not normally accessible to traditional methods for measuring the electronic [more...]

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 [more...]