Electron spill-out effect on third-order optical nonlinearity of metallic nanostructure

TL;DR

This paper investigates how electron spill-out influences the third-order nonlinear optical response of metallic nanostructures using quantum hydrodynamic theory, revealing significant effects on plasmon resonance and nonlinearity.

Contribution

It applies quantum hydrodynamic theory to analyze the impact of electron spill-out on third-order optical nonlinearity in metallic nanostructures, a novel approach in nonlinear plasmonics.

Findings

Electron spill-out significantly alters plasmon resonance.

Electron spill-out strongly affects third-order optical nonlinearity.

Quantum hydrodynamic theory effectively models these quantum effects.

Abstract

Over the last three decades, plasmonics using metallic nanostructures has become central to nanophotonics research. Recently, its targets have been extended to nonlinear optical phenomena. In a nonlinear regime, quantum mechanical effects, as exemplified by electron spill-out on the surface of nanostructures, significantly influence the optical response. Quantum hydrodynamic theory (QHT) is a promising basis for the analysis of nonlinear optical responses involving such quantum mechanical effects. Herein, QHT was applied to calculate the third-order optical nonlinearity of a spherical metallic nanostructure. The results demonstrate how electron spill-out strongly affects plasmon resonance and third-order optical nonlinearity.