Nanoplasmonics beyond Ohm's law

TL;DR

This paper develops a nonlocal, semi-classical hydrodynamic model for nanoplasmonics that captures quantum confinement effects beyond Ohm's law, impacting field enhancement and extinction in metallic nanostructures.

Contribution

It introduces a real-space formulation of equations-of-motion that extend beyond local response and Ohm's law, incorporating a new intrinsic length scale for nanoplasmonic modeling.

Findings

Nonlocal effects significantly alter extinction cross sections.

Field enhancement is affected by quantum confinement.

The framework applies to various nanostructures like particles, dimers, and surfaces.

Abstract

In tiny metallic nanostructures, quantum confinement and nonlocal response change the collective plasmonic behavior with important consequences for e.g. field-enhancement and extinction cross sections. We report on our most recent developments of a real-space formulation of an equation-of-motion that goes beyond the common local-response approximation and use of Ohm's law as the central constitutive equation. The electron gas is treated within a semi-classical hydrodynamic model with the emergence of a new intrinsic length scale. We briefly review the new governing wave equations and give examples of applying the nonlocal framework to calculation of extinction cross sections and field enhancement in isolated particles, dimers, and corrugated surfaces.