Nonlocal effective medium approximation for metallic nanorod metamaterials

TL;DR

This paper introduces an analytical nonlocal effective medium approximation for metallic nanorod metamaterials, capturing optical nonlocal effects and predicting coexistence of modes near epsilon-near-zero regions, which influence refraction properties.

Contribution

The work develops a novel nonlocal effective medium theory based on Mie scattering to accurately describe optical effects in metallic nanorod metamaterials, especially near epsilon-near-zero regions.

Findings

Predicts coexistence of two modes around epsilon-near-zero region

Shows strong nonlocal effects lead to both positive and negative refraction

Outside the coexistence region, local theory suffices to describe behavior

Abstract

We present an analytical nonlocal effective medium approximation to describe the optical nonlocal effects in metallic nanorod metamaterials based on Mie scattering theory. It is shown that the developed nonlocal effective medium theory can predict a coexistence state of two modes around the epsilon-near-zero region, where strong optical nonlocal effects lead to the behavior of both positive refraction and negative refraction in the nanorod metamaterials. Outside of the coexistence region, only one mode can be excited and its behavior can be well described using the local effective medium theory.