Quantum theory of electric polarization nonlinearity in metal nanofilms

TL;DR

This paper develops a quantum model to analyze how boundary conditions affect the nonlinear electric polarization response of metal nanofilms, revealing significant dependence on surface conditions.

Contribution

It introduces a quantum theoretical framework for electron confinement in metal nanofilms and explores the impact of boundary conditions on nonlinear polarization.

Findings

Nonlinear polarizability sign varies with boundary conditions

Boundary conditions significantly influence nonlinear response

Quantum effects are crucial in nanoscale polarization behavior

Abstract

We develop a quantum theory of electron confinement in metal nanofilms. The theory is used to compute the nonlinear response of the film to a static or low-frequency external electric field and to investigate the role of boundary conditions imposed on the metal surface. We find that the sign and magnitude of the nonlinear polarizability depends dramatically on the type of boundary condition used.