SAMOP 2023 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

Q: Fachverband Quantenoptik und Photonik

Q 22: Poster II

Q 22.68: Poster

Dienstag, 7. März 2023, 16:30–19:00, Empore Lichthof

Coulomb effects in ultrashort few electron pulses — •Stefan Meier, Jonas Heimerl, and Peter Hommelhoff — Department Physik, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 91058 Erlangen

Most electron-based microscopy methods benefit from a high spatial coherence of the electron beam used. The smaller the electron source, the higher the spatial coherence, allowing, for example, particularly small foci in the electron microscope. Tungsten needle tips represent such highly coherent electron sources, with effective source sizes in the subnanometer range. Moreover, electron emission can be triggered by femtosecond short laser pulses, providing a source of ultrashort electron pulses. In this contribution, we investigate the transverse coherence properties of such a pulsed source as a function of the emitted current [1]. We show that the effective source size grows due to Coulomb effects already for one emitted electron per pulse on average. In a next step, we consider by postselection only the electron pulses in which two electrons have been emitted. In this case we observe strong energy anticorrelation between both electrons due to the extreme spatial and temporal confinement of the electrons during emission. We report on the current status of these measurements and the implications that arise from them.

[1] S. Meier and P. Hommelhoff, ACS Photonics 9, 3083 (2022)