Restoring the Physical Meaning of Metamaterial Constitutive Parameters

TL;DR

This paper identifies the non-physical nature of effective parameters in metamaterial homogenization and proposes a method to restore their physical meaning by addressing homogenization artifacts related to magneto-electric coupling.

Contribution

It introduces a novel approach to correct homogenization artifacts, enabling physically meaningful constitutive parameters for metamaterials.

Findings

Homogenization artifacts are linked to magneto-electric coupling.

Restoring physical meaning improves metamaterial modeling.

Method clarifies the interpretation of effective parameters.

Abstract

Metamaterial homogenization is often based on implicit assumptions inspired to natural material models. Retrieved effective permittivity and permeability, however, are often non-physical, especially near the array resonances, of most interest for metamaterial applications. We explain here the nature of typical homogenization artifacts, relating them to an inherent form of magneto-electric coupling associated with the finite phase velocity along metamaterial arrays. Our findings allow restoring the proper definition and physical meaning of local constitutive parameters for metamaterials.