Magnetic control of a meta-molecule

Gavin B G Stenning,Robert W Eason,Lewis C Maple,Peter A J De Groot,Nikolay I Zheludev,Graham J Bowden,Simon A Gregory,Alberto Sposito

doi:10.1364/oe.21.001456

Abstract

Metamaterials offer the prospect of new science and applications. They have been designed by shaping or changing the material of the individual meta-molecules to achieve properties not naturally attainable. Composite meta-molecules incorporating a magnetic component offer new opportunities. In this work we report on the interaction between a non-magnetic split ring resonator (SRR) and a thin film of yttrium iron garnet (YIG). Strong hybridized resonances are observed. While the SRR is characterized by a magnetic and electric resonance, in practice, it is found that the YIG couples strongly to this symmetric (electric) mode of the SRR. It is also demonstrated that the anti-crossing region provides fertile ground for the creation of elementary excitations such as backward volume magnetostatic waves.

Highlights

Metamaterials are man-made patterned structures which exhibit unusual electromagnetic properties
It has been demonstrated that coplanar waveguide (CPW)-based composite split ring resonator (SRR) metamaterials, incorporating a magnetic component (YIG), can be tuned by applying a magnetic field
The coupling between the SRR and the yttrium iron garnet (YIG) gives rise to hybridization of the two resonances, yielding a frequency response similar to that of a Fano-resonance [26]

Summary

Introduction

Metamaterials are man-made patterned structures which exhibit unusual electromagnetic properties. A given metamaterial consists of a periodic array, in our case SRRs, providing a collective response to an electromagnetic wave. Such systems are often restricted to a narrow frequency band due to the resonant character of the individual meta-molecule. There are two differing resonances to be considered: that of the SRR and that of the YIG Since the latter is fielddependent, tunability of the composite structure can be achieved using an applied magnetic field. The results show that strong hybridization occurs between the SRR and YIG resonances The latter is interpreted using a simple two-state model, for an SRR and YIG film respectively [7,8]. Spin-waves, MSSWs and BVMSWs are incorporated into the two-state model

Experimental arrangement

Experimental results

Conclusions