Photonic Chern insulator through homogenization of an array of particles

TL;DR

This paper demonstrates how an array of gyromagnetic cylinders can be homogenized into a medium exhibiting topologically non-trivial photonic band gaps and edge states, enabling new topological metamaterials.

Contribution

It introduces a method to create photonic Chern insulators via homogenization of gyromagnetic particle arrays, applicable to various lattice types including disordered systems.

Findings

Array exhibits topologically non-trivial band gaps.

Homogenization yields an effective medium with peaked Berry curvature.

System supports one-way edge states.

Abstract

We propose a route towards creating a metamaterial that behaves as a photonic Chern insulator, through homogenization of an array of gyromagnetic cylinders. We show that such an array can exhibit non-trivial topological effects, including topologically non-trivial band gaps and one-way edge states, when it can be homogenized to an effective medium model that has the Berry curvature strongly peaked at the wavevector k=0. The non-trivial band topology depends only on the parameters of the cylinders and the cylinders' density, and can be realized in a wide variety of different lattices including periodic, quasi-periodic and random lattices. Our system provides a platform to explore the interplay between disorder and topology and also opens a route towards synthesis of topological meta-materials based on the self-assembly approach.