On effective electromagnetic parameters of artificial nanostructured magnetic materials

TL;DR

This paper investigates the conditions under which artificial nanostructured magnetic materials can be effectively characterized by permeability, highlighting limitations and the need for more complex models for certain geometries.

Contribution

It analyzes the effective magnetic response of various nanostructures and identifies restrictive conditions for simple permeability descriptions, proposing the necessity for advanced constitutive relations.

Findings

Effective permeability measurement is limited to specific conditions.

Simple permeability models are insufficient for complex nanostructures.

More comprehensive constitutive relations are required for accurate descriptions.

Abstract

In this paper we discuss effective material parameter description of new nanostructures designed to perform as artificial magnetic materials for vis- ible light. Among these structures there are various split-ring resonators, dual-bar structures, fishnet layers and other geometries. Artificial magnetic response in these structures appears due to weak spatial dispersion effects, and it is important to study the conditions under which the magnetic re- sponse can be adequately measured with effective permeability tensor. On the examples of dual bars and split rings we show that this is possible only under some quite restrictive conditions. In the general case, more compli- cated constitutive relations with more effective material parameters need to be developed.