Evidence for atomic-scale vibron-mediated electron bunching
Abstract
Due to the Coulomb blockade effect, electrons rarely bunch during transport, a phenomenon observed only in a few specially engineered mesoscopic configurations. In this work, we introduce an atomically resolved shot-noise study to demonstrate the possibility of electron bunching through vibrational coupling which takes place in an atomically sized nano-electro-mechanical system. Using tunnelling spectroscopy, we observe signatures of vibron-assisted tunnelling on an Fe impurity in BiSe. Notably, simultaneous shot-noise measurements at the centre of the vibrating impurity reveal super-Poissonian noise. In the absence of alternative sources of super-Poissonian noise, this implies vibronic-coupling-induced bunching of electrons during the tunnelling process through the impurity, as theoretically predicted decades ago. As a future outlook, if coherence between electrons can be implemented, vibron-mediated electron bunching at single atomic sites may be exploited as a local injection source of -paired electrons.
Cite
@article{arxiv.2511.11803,
title = {Evidence for atomic-scale vibron-mediated electron bunching},
author = {A. Maiti and M. Amato and V. S. Stolyarov and H. Aubin and J. Estève and F. Pistolesi and M. Aprili and F. Massee},
journal= {arXiv preprint arXiv:2511.11803},
year = {2025}
}