The application of topology in optics has led to a new paradigm in developing photonic devices with robust properties against disorder Although considerable progress on topological phenomena has been achieved in the classical domain, the realization of strong light-matter coupling in the quantum domain remains unexplored We demonstrate a strong interface between single quantum emitters and topological photonic states Our approach creates robust counterpropagating edge states at the boundary of two distinct topological photonic crystals We demonstrate the chiral emission of a quantum emitter into these modes and establish their robustness against sharp bends This approach may enable the development of quantum optics devices with built-in protection, with potential applications in quantum simulation and sensing

A topological quantum optics interface

Topological corner state (TCS) and topological edge state (TES) have provided new approaches to control the propagation of light. The construction of topological coupled cavity-waveguide system (TCCWS) based on TCS and TES is worth looking forward to, due to its research prospects in realizing high-performance micro-nano integrated photonic devices. In this Letter, TCCWS is proposed in two-dimensional (2D) photonic crystal (PC), which possesses strong optical localization, high quality factor and excellent robustness compared with the conventional coupled cavity-waveguide system (CCCWS). This work will provide the possibility to design high-performance logic gates, lasers, filters and other micro-nano integrated photonics devices and expand their applications.

Coupled cavity-waveguide system based on topological corner state and edge state

Logic gates based on edge states in gyromagnetic photonic crystal

Variation of Topological Edge States of 2D Honeycomb Lattice Photonic Crystals

https://iopscience.iop.org/article/10.35848/1882-0786/ab6934/pdf

An approximate theoretical explanation for super-resolution imaging of two-dimensional photonic quasi-crystal flat lens

Optical topological insulators (OTIs) based on photonic crystals with ${C}_{6}$ symmetry are of interest for applications in integrated optics, offering special properties such as robustness, backscattering suppression, and defect immunity. These systems can be created with all-dielectric materials and no magnetic field, but progress is held back by technical difficulties. This study reveals the relationship between topological properties and structural parameters, and thus how to make OTIs with better adjustability by changing only the diameter of the cylinders in the basic structural unit of the photonic crystal.

Topological Edge State in the Two-Dimensional Stampfli-Triangle Photonic Crystals

The topological corner state (TCS) and topological edge state (TES) have created new approaches to manipulate the propagation of light. The construction of a topological coupled cavity-waveguide (TCCW) based on the TCS and TES is worth looking forward to, due to its research prospects in realizing high-performance micro-nano integrated photonic devices. In this Letter, the TCCW is proposed in two-dimensional (2D) photonic crystal (PC), which possesses strong optical localization, high quality factor, and excellent robustness compared with the conventional coupled cavity-waveguide (CCCW). This work will pave the way toward designing high-performance logic gates, lasers, filters, and other micro-nano integrated photonics devices and expanding their applications.

Coupled cavity-waveguide based on topological corner state and edge state.

Fragile topology (FT) opens a new direction in topological photonics, but a new type of photonic crystal (PC) with FT remains to be proposed. In this Letter, the double-site honeycomb lattice (DSHL) PC is proposed by rotating the double dielectric rods (DDR) six times, forming unit cell, and then arraying the unit cells in a triangular lattice. Quantum spin Hall effect occurs by manipulating the DDR in the tangential and radial directions of the unit cell. First, the band structures of DSHL PCs with different structural parameters are calculated, and the laws of topological phase transition are analyzed statistically. Then, to prove the FT properties of two groups of topological nontrivial DSHL PCs, the Wannier-center positions of the bulk bands are calculated by the Wilson–Loop method. Finally, the topological edge states and two groups of topological corner states, which are in the same bulk-state bandgap, are realized successfully. The DSHL PC provides good platforms for both the research of topological photonics and the device design and application, which has a broad prospect.

Yuchen Peng

Papers

Topological Edge State in the Two-Dimensional Stampfli-Triangle Photonic Crystals

Coupled cavity-waveguide system based on topological corner state and edge state

Variation of Topological Edge States of 2D Honeycomb Lattice Photonic Crystals

Coupled cavity-waveguide based on topological corner state and edge state.

Fragile topology in double-site honeycomb lattice photonic crystal.