Magnetic plasmons in plasmonic nanostructures: An overview

The magnetic response of most natural materials, characterized by magnetic permeability, is generally weak. Particularly, in the optical range, the weakness of magnetic effects is directly related to the asymmetry between electric and magnetic charges. Harnessing artificial magnetism started with a pursuit of metamaterial design exhibiting magnetic properties. The first demonstration of artificial magnetism was given by a plasmonic nanostructure called split-ring resonators. Engineered circulating currents form magnetic plasmons, acting as the source of artificial magnetism in response to external electromagnetic excitation. In the past two decades, magnetic plasmons supported by plasmonic nanostructures have become an active topic of study. This Perspective reviews the latest studies on magnetic plasmons in plasmonic nanostructures. A comprehensive summary of various plasmonic nanostructures supporting magnetic plasmons, including split-ring resonators, metal-insulator-metal structures, metallic deep groove arrays, and plasmonic nanoclusters, is presented. Fundamental studies and applications based on magnetic plasmons are discussed. The formidable challenges and the prospects of the future study directions on developing magnetic plasmonic nanostructures are proposed.

Automated summary

The magnetic response of natural materials is generally weak, especially in the optical range. Artificial magnetism is achieved through metamaterial design and the use of plasmonic nanostructures like split-ring resonators. These structures generate magnetic plasmons, which respond to external electromagnetic stimulation. The study of magnetic plasmons has become an active area of research in the past two decades, with various plasmonic nanostructures supporting magnetic plasmons. This Perspective reviews the latest studies, summarizes different nanostructures, discusses applications, and proposes future directions.