Harnessing Plasmonic Interference for Nanoscale Ultrafast Electron Sources

TL;DR

This paper presents a novel plasmonic nanostructure that uses interference effects to produce ultrafast, highly focused electron sources with extremely low emittance, suitable for advanced microscopy and accelerator applications.

Contribution

It introduces a geometrically flat nanoscale electron source leveraging plasmonic interference for ultrafast, low-emittance electron emission, advancing nanoscale electron source technology.

Findings

Achieved less than 40 pm-rad rms normalized transverse emittance.

Generated a 50 nm rms emission area via plasmonic interference.

Enabled simultaneous nanometer and femtosecond confinement of electrons.

Abstract

In this paper we demonstrate the use of plasmonic focusing in conjunction with non-linear photoemisison to develop geometrically flat nanoscale electron sources with less than 40 pm-rad root mean squared (rms) normalized transverse emittance. Circularly polarized light is incident on a gold Archimedean spiral structure to generate surface-plasmon-polaritons which interfere coherently at the center resulting in a 50 nm rms emisison area. Such a nanostructured flat surface enables simultaneous spatio-temporal confinement of emitted electrons at the nanometer and femtosecond level and can be used as an advanced electron source for high-repetition-rate ultrafast electron diffraction and microscopy experiments as well as next-generation of miniaturized particle accelerators.