Chiral optical response of planar and symmetric nanotrimers enabled by heteromaterial selection

TL;DR

This paper demonstrates a new method to induce optical chirality in symmetric nanostructures by heteromaterial composition, enabling control over light polarization interactions at the nanoscale.

Contribution

It introduces a novel approach to generate optical chirality in symmetric nanostructures through heteromaterial selection, breaking symmetry without geometric chirality.

Findings

Chiral optical response observed in symmetric nanostructures.

Experimental and numerical validation with silicon and gold nanoparticles.

Potential for designing 2D chiral media at the nanoscale.

Abstract

Chirality is an intriguing property of certain molecules, materials or artificial nanostructures, which allows them to interact with the spin angular momentum of the impinging light field. Due to their chiral geometry, they can distinguish between left- and right-hand circular polarization states or convert them into each other. Here, we introduce a novel approach towards optical chirality, which is observed in individual two-dimensional and geometrically mirror-symmetric nanostructures. In this scheme, the chiral optical response is induced by the chosen heterogeneous material composition of a particle assembly and the corresponding resonance behavior of the constituents it is built from, which breaks the symmetry of the system. As a proof of principle, we investigate such a structure composed of individual silicon and gold nanoparticles both experimentally as well as numerically. Our proposed concept constitutes a novel approach for designing two-dimensional chiral media tailored at the nanoscale.