SKM 2023 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 37: Poster: Ultrafast Electron Dynamics at Surface and Interfaces II

O 37.5: Poster

Dienstag, 28. März 2023, 18:00–20:00, P2/EG

Investigation of low-temperature electron emission properties from sharp needle tips — •Manuel Knauft, Stefan Meier, Norbert Schönenberger, and Peter Hommelhoff — Department Physik, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 91058 Erlangen

Spectroscopic and microscopic techniques benefit from the small linewidth of coherent electron sources with high brightness. Reducing the operating temperature of the emitter is known to positively influence coherence of field emitted electron beams. This is especially true for superconducting needle tips as shown for niobium [1].

We present an experimental setup capable of cooling electron emitters to liquid helium temperature in ultra-high vacuum. Irradiation of samples with ultrashort laser pulses is possible through optical access to the chamber. Detection of charged particles is realized by a multi-channel plate. First results for sharp needle tips of various materials are shown. In particular, we investigate the emission characteristics and compare them for field emission and laser triggered emission as a function of temperature.

[1] Nagaoka et al., Nature 396, 557 (1998)