Nonlinear photoemission from metal surfaces induced by short laser pulses: the effect of field enhancement by surface plasmons

TL;DR

This paper investigates how surface plasmons enhance nonlinear photoemission from metals under short laser pulses, revealing complex electron spectra that challenge standard models but are explained by near-field effects.

Contribution

It introduces a theoretical framework based on plasmon-induced near-field effects to explain nonlinear photoemission spectra that deviate from traditional predictions.

Findings

Observed electron spectra extend beyond standard model predictions.

Theoretical analysis aligns qualitatively with experimental data across intensities.

Surface plasmon effects significantly influence electron emission processes.

Abstract

Nonlinear electron emission processes induced by surface plasmon oscillations have been studied both experimentally and theoretically. The measured above-threshold electron spectra extend up to energies whose appearance cannot be explained solely by standard non-perturbative methods, which predict photon energy separated discrete energy line spectra with the known fast fall - plateau - cutoff envelope shape, even when taking the large field enhancement into account. The theoretical analysis of our data, based on the concept of plasmon-induced near-field effects, gives reasonably good explanation and qualitative agreement in the whole intensity range.