Scheme to Achieve Silicon Topological Photonics

TL;DR

This paper demonstrates a novel approach to realize topological photonic states using silicon, a common dielectric, by deforming a honeycomb lattice into a triangular lattice of hexagons, revealing new topological properties and edge states.

Contribution

It introduces a method to achieve silicon-based topological photonics through lattice deformation, leveraging pseudo time reversal symmetry and circular polarization as pseudo spin.

Findings

Identification of pseudo spin-resolved Berry curvatures.

Observation of helical edge states with Poynting vector characterization.

Demonstration of topological photonic states in silicon structures.

Abstract

We derive in the present work topological photonic states purely based on silicon, a conventional dielectric material, by deforming a honeycomb lattice of silicon cylinders into a triangular lattice of cylinder hexagons. The photonic topology is associated with a pseudo time reversal (TR) symmetry constituted by the TR symmetry respected in general by the Maxwell equations and the $C_6$ crystal symmetry upon design, which renders the Kramers doubling in the present photonic system with the role of pseudo spin played by the circular polarization of magnetic field in the transverse magnetic mode. We solve Maxwell equations, and demonstrate new photonic topology by revealing pseudo spin-resolved Berry curvatures of photonic bands and helical edge states characterized by Poynting vectors.