Robust Edge States in Amorphous Gyromagnetic Photonic Lattices

Abstract

We numerically study amorphous analogues of a two-dimensional photonic Chern insulator. The amorphous lattices consist of gyromagnetic rods that break time-reversal symmetry, with the lattice sites generated by a close-packing algorithm. The level of short-range order is adjustable, and there is no long-range order. The topologically nontrivial gaps of the photonic Chern insulator are found to persist into the amorphous regime, so long as there is sufficient short-range order. Strongly nonreciprocal robust transmission occurs via edge states, which are shown to propagate ballistically despite the absence of long-range order, and to be exponentially localized along the lattice edge. Interestingly, there is an enhancement of nonreciprocal transmission even at very low levels of short-range order, where there are no discernable spectral gaps.

6 pages, 4 figures

References in corpus (11)

• Topological Photonics
• Scheme to Achieve Silicon Topological Photonics
• Reflection-Free One-Way Edge Modes in a Gyromagnetic Photonic Crystal
• Topological Acoustics
• Analogs of quantum Hall effect edge states in photonic crystals
• Topological Anderson Insulator
• Designer disordered materials with large complete photonic band gaps
• Disorder-induced Floquet Topological Insulators
• Topological Photonic Quasicrystals: Fractal Topological Spectrum and Protected Transport
• Measurement of a topological edge invariant in a microwave network
• Understanding the Frequency Distribution of Mechanically Stable Disk Packings

Cited by in corpus (3)

• A brief review of topological photonics in one, two, and three dimensions
• Topological Anderson insulators in an Ammann-Beenker quasicrystal and a snub-square crystal
• Density-driven higher-order topological phase transitions in amorphous solids