Experimental demonstration of an anomalous Floquet topological insulator based on negative-index media

Abstract

Photonic and acoustic topological insulators exhibiting one-way transportation that is robust against defects and impurities are typically realized in coupled arrays of two-dimensional ring resonators. These systems have produced a series of applications, including optical isolators, delay lines, and lasers. However, the structures are complicated because an additional coupler ring between neighboring rings is needed to construct photonic pseudo-spin. In this work, a photonic analogue of the quantum spin Hall effect is proposed and experimentally demonstrated in an anomalous Floquet topological insulator in the microwave regime. This improved design takes advantage of the efficient and backward coupling of negative-index media. The results contribute to the understanding of topological structures in metamaterials and point toward a new direction for constructing useful topological photonic devices.

arXiv comment8 pages, 13 figures

References in corpus (21)

• Quantum Spin Hall Effect in Graphene
• $Z_2$ Topological Order and the Quantum Spin Hall Effect
• Photonic Floquet Topological Insulators
• Possible Realization of Directional Optical Waveguides in Photonic Crystals with Broken Time-Reversal Symmetry
• Photonic Analogue of Two-dimensional Topological Insulators and Helical One-Way Edge Transport in Bi-Anisotropic Metamaterials
• Imaging topological edge states in silicon photonics
• Scheme to Achieve Silicon Topological Photonics
• Robust optical delay lines via topological protection
• Reflection-Free One-Way Edge Modes in a Gyromagnetic Photonic Crystal
• Efficient Light Funneling based on the non-Hermitian Skin Effect
• A topological quantum optics interface
• Visualization of unidirectional optical waveguide using topological photonic crystals made of dielectric material
• Topologically protected acoustic helical edge states and interface states in strongly coupled metamaterial ring lattices
• A topological source of quantum light
• Crystalline metamaterials for topological properties at subwavelength scales
• Hyperbolic Metamaterials: From Dispersion Manipulation to Application
• Third-harmonic generation in photonic topological metasurfaces
• Network Models of Photonic Floquet Topological Insulators
• Reconfigurable topological phases in next-nearest-neighbor coupled resonator lattices
• Topological transitions in continuously-deformed photonic crystals
• Universal sign-control of coupling in tight-binding lattices