Scattering-Free Optical Edge States between Heterogeneous Photonic Topological Insulators

TL;DR

This paper introduces three photonic platforms that emulate topological insulators and demonstrates that interfaces between different types support scattering-free surface states, enabling robust photonic pathways.

Contribution

It presents novel photonic platforms for emulating quantum topological phases and shows that heterogeneous interfaces support protected, scattering-free surface states.

Findings

Interfaces support scattering-free surface states

Surface states are characterized by spin and valley degrees of freedom

Pathways are robust through complex circuits

Abstract

We propose a set of three simple photonic platforms capable of emulating quantum topologically insulating phases corresponding to Hall, spin-Hall, and valley-Hall effects. It is shown that an interface between any two of these heterogeneous photonic topological insulators supports scattering-free surface states. Spin and valley degrees of freedom characterizing such topologically protected surface waves determine their unique pathways through complex photonic circuits comprised of multiple heterogeneous interfaces.