Abstract
Point-projection microscopy (PPM) with low energy electrons is developing into a powerful tool for holographic reconstruction of individual proteins and solid state nanostructures. In combination with laser-based photo emission schemes, it offers the exciting prospect of ultrafast coherent electron holography of single nanostructures. Such experiments would greatly benefit from a freestanding electron source with femtosecond time resolution, few-nm emitter size, and good coherence properties. Here, we use plasmonic nanofocusing on a conical gold taper and multiphoton photoemission from the taper apex to create such a source. It is implemented in a PPM setup and used to record in-line holograms of thin bundles of single-walled carbon nanotubes, demonstrating an effective emitter radius of less than 5 nm. We show that the same concept can also be transferred to tungsten tips, offering further improvements in emitter size and brightness. Numerical simulations show that such an ultrafast, low-energy electron source presents a highly interesting tool for probing optical fields at surfaces with nanometer spatial and femtosecond time resolution.
Item Type: | Journal article |
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Faculties: | Chemistry and Pharmacy > Department of Chemistry |
Subjects: | 500 Science > 540 Chemistry |
ISSN: | 2330-4022 |
Language: | English |
Item ID: | 67565 |
Date Deposited: | 19. Jul 2019, 12:22 |
Last Modified: | 04. Nov 2020, 13:49 |