Coupling phenomena and collective effects in resonant meta-molecules supporting plasmonic and magnetic functionalities: a review

TL;DR

This review discusses the fundamental principles and applications of magneto-optic and opto-magnetic metamaterials, focusing on collective effects and coupling phenomena in nanoscale structures that enable advanced control of electromagnetic and magnetic properties.

Contribution

It provides a comprehensive overview of how magnetic materials can be used in metamaterials to enhance optical magnetism and manipulate light-matter interactions at the nanoscale, highlighting recent advances and future challenges.

Findings

Coupling effects in magnetic meta-molecules can enhance optical magnetism.

Surface lattice resonances influence collective electromagnetic responses.

Magneto-plasmonic crystals enable active control of light and magnetic interactions.

Abstract

We review both the fundamental aspects and the applications of functional magneto-optic and opto-magnetic metamaterials displaying collective and coupling effects on the nanoscale, where the concepts of optics and magnetism merge to produce unconventional phenomena. The use of magnetic materials instead of the usual noble metals allows for an additional degree of freedom for the control of electromagnetic field properties, as well as it allows light to interact with the spins of the electrons and to actively manipulate the magnetic properties of such nanomaterials. In this context, we explore the concepts of near-field coupling of plasmon modes in magnetic meta-molecules, as well as the effect of excitation of surface lattice resonances in magneto-plasmonic crystals. Moreover, we discuss how these coupling effects can be exploited to artificially enhance optical magnetism in plasmonic meta-molecules and crystals. Finally, we highlight some of the present challenges and provide a perspective on future directions of the research towards photon-driven fast and efficient nanotechnologies bridging magnetism and optics beyond current limits.