Two electrons interacting at a mesoscopic beam splitter

verfasst von
Niels Ubbelohde, Lars Freise, Elina Pavlovska, Peter G. Silvestrov, Patrik Recher, Martins Kokainis, Girts Barinovs, Frank Hohls, Thomas Weimann, Klaus Pierz, Vyacheslavs Kashcheyevs
Abstract

The nonlinear response of a beam splitter to the coincident arrival of interacting particles enables numerous applications in quantum engineering and metrology. Yet, it poses considerable challenges to control interactions on the individual particle level. Here, we probe the coincidence correlations at a mesoscopic constriction between individual ballistic electrons in a system with unscreened Coulomb interactions and introduce concepts to quantify the associated parametric nonlinearity. The full counting statistics of joint detection allows us to explore the interaction-mediated energy exchange. We observe an increase from 50% up to 70% in coincidence counts between statistically indistinguishable on-demand sources and a correlation signature consistent with the independent tomography of the electron emission. Analytical modelling and numerical simulations underpin the consistency of the experimental results with Coulomb interactions between two electrons counterpropagating in a quadratic saddle potential. Coulomb repulsion energy and beam splitter dispersion define a figure of merit, which in this experiment is demonstrated to be sufficiently large to enable future applications, such as single-shot in-flight detection and quantum logic gates.

Externe Organisation(en)
Physikalisch-Technische Bundesanstalt (PTB)
University of Latvia
Technische Universität Braunschweig
Laboratory for Emerging Nanometrology Braunschweig (LENA)
Typ
Artikel
Journal
Nature nanotechnology
Band
18
Seiten
733-740
Anzahl der Seiten
8
ISSN
1748-3395
Publikationsdatum
07.2023
Publikationsstatus
Veröffentlicht
Peer-reviewed
Ja
ASJC Scopus Sachgebiete
Physik der kondensierten Materie, Bioengineering, Atom- und Molekularphysik sowie Optik, Werkstoffwissenschaften (insg.), Elektrotechnik und Elektronik, Biomedizintechnik
Elektronische Version(en)
https://doi.org/10.48550/arXiv.2210.03632 (Zugang: Offen)
https://doi.org/10.1038/s41565-023-01370-x (Zugang: Geschlossen)