Magneto-optical response in bimetallic metamaterials

TL;DR

This paper demonstrates that bimetallic nano-ring resonators made of gold and nickel can produce significant magneto-optical effects, enabling compact magnetic sensors and integrated photonic devices.

Contribution

It introduces a novel bimetallic metamaterial design that balances magneto-optical enhancement with plasmonic dissipation, achieving effects comparable to continuous films.

Findings

Resonant Faraday rotation achieved in bimetallic nano-ring arrays.

Nickel sections as small as 6% of surface produce significant effects.

Potential applications in compact sensors and integrated photonics.

Abstract

We demonstrate resonant Faraday polarization rotation in plasmonic arrays of bimetallic nano-ring resonators consisting of Au and Ni sections. This metamaterial design allows to optimize the trade-off between the enhancement of magneto-optical effects and plasmonic dissipation. Although Ni sections correspond to as little as ~6% of the total surface of the metamaterial, the resulting magneto-optically induced polarization rotation is equal to that of a continuous film. Such bimetallic metamaterials can be used in compact magnetic sensors, active plasmonic components and integrated photonic circuits.