High energy photoelectron emission from gases using plasmonics enhanced near-fields

TL;DR

This paper theoretically investigates how plasmonic enhanced near-fields can generate high-energy photoelectrons from noble gases, showing potential for efficient electron acceleration using current femtosecond laser technology.

Contribution

It introduces a theoretical model of photoelectron emission in noble gases driven by plasmonic near-fields, highlighting the role of nonhomogeneous fields in extending electron energy spectra.

Findings

Enhanced near-fields significantly increase photoelectron energies.

Nonhomogeneous fields influence above threshold ionization (ATI).

Classical and quantum calculations agree on key results.

Abstract

We study theoretically the photoelectron emission in noble gases using plasmonic enhanced near-fields. We demonstrate that these fields have a great potential to generate high energy electrons by direct mid-infrared laser pulses of the current femtosecond oscillator. Typically, these fields appear in the surroundings of plasmonic nanostructures, having different geometrical shape such as bow-ties, metallic waveguides, metal nanoparticles and nanotips, when illuminated by a short laser pulse. In here, we consider metal nanospheres, in which the spatial decay of the near-field of the isolated nanoparticle can be approximated by an exponential function according to recent attosecond streaking measurements. We establish that the strong nonhomogeneous character of the enhanced near-field plays an important role in the above threshold ionization (ATI) process and leads to a significant extension in the photoelectron spectra. In this work, we employ the time dependent Schr\"odinger equation in reduced dimensions to calculate the photoelectron emission of xenon atoms in such enhanced near-field. Our findings are supported by classical calculations.