Controlling electrically-stimulated quantum light sources (QLS) is key for developing integrated and low-scale quantum devices. The mechanisms leading to quantum emission are complex, as a large number of electronic states of the system impacts the emission dynamics. Here, we use a scanning tunneling microscope (STM) to excite a model QLS, namely a single molecule. The luminescence spectra reveal two lines, associated to the emission of the neutral and positively charged molecule, both exhibiting single-photon source behavior. In addition, we find a correlation between the charged and neutral molecule's emission, the signature of a photon cascade. By adjusting the charging/discharging rate, we can control these emission statistics. This generic strategy is further established by a rate equation model revealing the complex internal dynamics of the molecular junction.
@article{arxiv.2402.17536,
title = {Electrically driven cascaded photon-emission in a single molecule},
author = {Katharina Kaiser and Anna Rosławska and Michelangelo Romeo and Fabrice Scheurer and Tomáš Neuman and Guillaume Schull},
journal= {arXiv preprint arXiv:2402.17536},
year = {2024}
}