Artificial flat band systems: from lattice models to experiments

Abstract

Certain lattice wave systems in translationally invariant settings have one\nor more spectral bands that are strictly flat or independent of momentum in the\ntight binding approximation, arising from either internal symmetries or\nfine-tuned coupling. These flat bands display remarkable strongly-interacting\nphases of matter. Originally considered as a theoretical convenience useful for\nobtaining exact analytical solutions of ferromagnetism, flat bands have now\nbeen observed in a variety of settings, ranging from electronic systems to\nultracold atomic gases and photonic devices. Here we review the design and\nimplementation of flat bands and chart future directions of this exciting\nfield.\n