Hybrid topological photonic crystals

TL;DR

This paper reports the experimental discovery of hybrid topological photonic crystals that simultaneously host quantum anomalous Hall and valley Hall phases, enabling novel multiplexing and frequency-dependent control of edge photon transport.

Contribution

It introduces the first experimental realization of hybrid topological phases in photonic crystals with coexisting quantum anomalous Hall and valley Hall effects in different band gaps.

Findings

Coexistence of chiral and valley Hall edge states in different frequency ranges.

Experimental verification of hybrid topological phases.

Potential for frequency-dependent filtering and manipulation of edge photons.

Abstract

Photonic topological phases offering unprecedented manipulation of electromagnetic waves have attracted much research interest which, however, have been mostly restricted to a single band gap. Here, we report on the experimental discovery of hybrid topological photonic crystals which host simultaneously quantum anomalous Hall and valley Hall phases in different photonic band gaps. The underlying hybrid topological phase manifests itself in the edge responses as the coexistence of the chiral edge states and valley Hall edge states in different frequency ranges. We experimentally verify such an emergent phenomenon and show that such a feature enables novel multiplexing of photon transport in the edge channels. Our study reveals a situation with coexisting topology of distinct nature in a single photonic system that may enable frequency-dependent filtering and manipulation of topological edge photons.