Researchers at the Laboratoire de Physique des Solides (CNRS/Université Paris-Saclay), in collaboration with C2N, the University of Bordeaux and MIPT, have provided the first atomic-scale experimental evidence that vibrations of matter can cause electrons to travel in correlated groups instead of independently.
Electrons are usually regarded as solitary travelers. Because they carry the same negative electric charge, they strongly repel one another and typically tunnel through nanoscale systems one at a time. However, theoretical studies predicted two decades ago that strong coupling between electrons and atomic vibrations could alter this behavior and lead to the temporary bunching of electrons during transport.
To test this prediction, the researchers investigated an iron impurity embedded in the semiconductor Bi₂Se₃ using a specially designed low-temperature scanning tunneling microscope. Beyond measuring the average tunneling current, the instrument is capable of detecting tiny current fluctuations known as shot noise, which directly reveal how electrons move through a system.
The measurements showed clear signatures of transport assisted by local vibrational excitations, known as vibrons. When an electron tunnels through the impurity, it excites these vibrations, which persist briefly after the electron has passed. During this short time window, the local electronic environment is modified in a way that makes it easier for subsequent electrons to tunnel, inducing electron bunching.
This effect was revealed through the observation of super-Poissonian shot noise, a hallmark of electron bunching that exceeds the fluctuations expected for independent electrons. The results provide the first direct atomic-scale evidence of vibron-mediated electron bunching, a phenomenon that had remained elusive until now.
In the longer term, the ability to generate correlated electrons from individual atomic sites could open new opportunities for electron quantum optics and future quantum technologies that rely on controlled many-electron states.
Contributors
Laboratoire de Physique des Solides (LPS, Université Paris-Saclay, CNRS)
A. Maiti, M. Amato, J. Estève, M. Aprili, F. Massee
Centre de Nanosciences et de Nanotechnologies (C2N, Université Paris-Saclay, CNRS)
H. Aubin
Laboratoire Ondes et Matière d’Aquitaine (LOMA, Université de Bordeaux, CNRS)
F. Pistolesi
Moscow Institute of Physics and Technology (MIPT)
V. S. Stolyarov
References
A. Maiti, M. Amato, V. S. Stolyarov, H. Aubin, J. Estève, F. Pistolesi, M. Aprili, and F. Massee, Evidence for Atomic-Scale Vibron-Mediated Electron Bunching.,Physical Review Letters 136, 236501 (2026). DOI: 10.1103/PhysRevLett.136.236501
Featured in Physics Magazine: Vibrations Make Electrons Team Up (June 10, 2026).
Contact
Freek Massee : freek.massee@universite-paris-saclay.fr