Electronic temperature and two-electron processes in overbias plasmonic emission from tunnel junctions
Abstract
The accurate determination of electronic temperatures in metallic nanostructures is essential for many technological applications, like plasmon-enhanced catalysis or lithographic nanofabrication procedures. In this Letter we demonstrate that the electronic temperature can be accurately measured by the shape of the tunnel electroluminescence emission edge in tunnel plasmonic nanocavities, which follows a universal thermal distribution with the bias voltage as the chemical potential of the photon population. A significant deviation between electronic and lattice temperatures is found below 30 K for tunnel currents larger than 15 nA. This deviation is rationalized as the result of a two-electron process in which the second electron excites plasmon modes with an energy distribution that reflects the higher temperature following the first tunneling event. These results dispel a long-standing controversy on the nature of overbias emission in tunnel junctions and adds a new method for the determination of electronic temperatures and quasiparticle dynamics.
Cite
@article{arxiv.2102.10817,
title = {Electronic temperature and two-electron processes in overbias plasmonic emission from tunnel junctions},
author = {Alberto Martín-Jiménez and Koen Lauwaet and Óscar Jover and Daniel Granados and Andrés Arnau and Vyacheslav M. Silkin and Rodolfo Miranda and Roberto Otero},
journal= {arXiv preprint arXiv:2102.10817},
year = {2021}
}