Photonic Analogue of Two-dimensional Topological Insulators and Helical One-Way Edge Transport in Bi-Anisotropic Metamaterials

TL;DR

This paper demonstrates that carefully designed bi-anisotropic metamaterials can emulate two-dimensional topological insulators, supporting helical edge states that enable robust one-way photonic transport unaffected by disorder.

Contribution

It introduces a photonic analogue of topological insulators using metamaterials, enabling robust edge transport in electromagnetic systems.

Findings

Creation of photonic phases with helical edge states

Support for one-way photonic transport

Robustness against disorder in edge states

Abstract

Recent progress in understanding the topological properties of condensed matter has led to the discovery of time-reversal invariant topological insulators. Because of limitations imposed by nature, topologically non-trivial electronic order seems to be uncommon except in small-band-gap semiconductors with strong spin-orbit interactions. In this Article we show that artificial electromagnetic structures, known as metamaterials, provide an attractive platform for designing photonic analogues of topological insulators. We demonstrate that a judicious choice of the metamaterial parameters can create photonic phases that support a pair of helical edge states, and that these edge states enable one-way photonic transport that is robust against disorder.