Compact Topological Edge States in Flux-Dressed Graphene-Like Photonic Lattices

We report the existence of compact topological edge states on flux-dressed photonic graphene ribbons [1]. Robust localization is achieved through a synergy of Aharonov- Bohm caging and topological protection mechanisms. The topological nontriviality of the compact edge states predicted by theoretical derivations is confirmed by experimental estimation of an integer Zak phase obtained from the mean chiral displacement. Experiments are performed using direct femtosecond laser writing of a graphene ribbon photonic lattice having 0 or synthetic magnetic flus. Mode stability is demonstrated by its exceptional localization and resilience to fabrication tolerances and input phase variations. Demonstration of the compact edge modes opens the door to exploitation of the synergy between flat-band physics and topology in secure information transfer and high-temperature superconductivity.