Coupled magnetic plasmons in metamaterials

TL;DR

This paper reviews recent advances in magnetic plasmonics within metamaterials, emphasizing how coupling between magnetic resonators leads to new phenomena and potential applications like broadband tunable materials.

Contribution

It highlights the importance of resonator coupling effects in magnetic metamaterials, moving beyond the effective media approximation to reveal novel resonance behaviors and applications.

Findings

Coupling causes multiple discrete resonance modes.

Strong coupling extends resonances into a continuous frequency band.

Coupled systems enable broadband and tunable magnetic metamaterials.

Abstract

Magnetic metamaterials consist of magnetic resonators smaller in size than their excitation wavelengths. Their unique electromagnetic properties were characterized by the effective media theory at the early stage. However, the effective media model does not take into account the interactions between magnetic elements; thus, the effective properties of bulk metamaterials are the result of the "averaged effect" of many uncoupled resonators. In recent years, it has been shown that the interaction between magnetic resonators could lead to some novel phenomena and interesting applications that do not exist in conventional uncoupled metamaterials. In this paper, we will give a review of recent developments in magnetic plasmonics arising from the coupling effect in metamaterials. For the system composed of several identical magnetic resonators, the coupling between these units produces multiple discrete resonance modes due to hybridization. In the case of a system comprising an infinite number of magnetic elements, these multiple discrete resonances can be extended to form a continuous frequency band by strong coupling. This kind of broadband and tunable magnetic metamaterial may have interesting applications. Many novel metamaterials and nanophotonic devices could be developed from coupled resonator systems in the future.