Observation of STM-luminescence induced by THz-field-driven tunneling electrons

Abstract

In this work, we developed a novel nano-spectroscopy technique, entitled terahertz-field-driven scanning tunneling luminescence (THz-STL) spectroscopy, based on a scanning tunneling microscope (STM). THz-STL spectroscopy combines two cutting-edge STM techniques, THz-STM and STL spectroscopy, and enables to investigate atomic-scale energy dissipations triggered by a THz single-cycle pulse. We introduced single-cycle THz pulses into an STM junction (Au tip and Ag(111)) and measured visible photons generated by THz-field-driven electrons. By utilizing this technique, we detected the radiative decay of a localized plasmon excited by THz-field-driven electrons and clarified mechanistic differences in plasmon excitation between field- and DC-driven electrons.