Antihelical Edge States in Two-dimensional Photonic Topological Metals

Abstract

Topological edge states are the core of topological photonics. Here we introduce the antihelical edge states of time-reversal symmetric topological metals and propose a photonic realization in an anisotropic square lattice of coupled ring resonators, where the clockwise and counterclockwise modes play the role of pseudospins. The antihelical edge states robustly propagate across the corners toward the diagonal of the square lattice: The same (opposite) pseudospins copropagate in the same (opposite) direction on the parallel lattice boundaries; the different pseudospins separate and converge at the opposite corners. The antihelical edge states in the topological metallic phase alter to the helical edge states in the topological insulating phase under a metal-insulator phase transition. The antihelical edge states provide a unique manner of topologically-protected robust light transport applicable for topological purification. Our findings create new opportunities for topological photonics and metamaterials.

8 pages, 7 figures

References in corpus (4)

• Topological Photonics
• Observation of photonic antichiral edge states
• Observation of Antichiral Edge States in a Circuit Lattice
• Optically reconfigurable quantum spin-valley Hall effect of light in coupled nonlinear ring resonator lattice

Cited by in corpus (15)

• Topological Non-Hermitian skin effect
• Universal competitive spectral scaling from the critical non-Hermitian skin effect
• Photonic corner skin modes
• Edge State, Band Topology, and Time Boundary Effect in the Fine-Grained Categorization of Chern Insulators
• Observation of non-Hermitian antichiral edge currents
• Non-Hermitian Second-Order Topological Phases and Bipolar Skin Effect in Photonic Kagome Crystals
• Pseudo-Hermiticity protects the energy-difference conservation in the scattering
• Two-Dimensional Higher-Order Topological Metals
• Two-dimensional Weyl nodal-line semimetal and antihelical edge states in a modified Kane-Mele model
• Anti-helical edge magnons in patterned antiferromagnetic thin film
• Tunable Aharonov-Bohm cages through anti-$\mathcal{P}\mathcal{T}$-symmetric imaginary couplings
• Berry curvature inside parity-time-symmetry protected exceptional surface
• Flat band and $\eta$-pairing states in one-dimensional Moiré Hubbard model
• Disorder-induced instability of a Weyl nodal loop semimetal towards a diffusive topological metal with protected multifractal surface states
• Synchronized in-gap edge states and robust copropagation in topological insulators without magnetic flux