Localized States Emerging from Singular and Nonsingular Flat Bands in a Frustrated Fractal‐Like Photonic Lattice (Advanced Optical Materials 9/2022)

In article number 2102523, Haissam Hanafi, Philip Menz, and Cornelia Denz report on the experimental demonstration of localized states that propagate diffractionless in a fractal‐like photonic lattice fabricated by femtosecond direct laser writing. These states arise from multiple flat bands of singular and nonsingular nature in the spectrum of the geometrically frustrated lattice. This research reveals fundamental aspects of flat band physics and paves the way for photonic spin liquid ground states.