Systematic construction of topological flat-band models by molecular-orbital representation

Abstract

On the basis of the "molecular-orbital" representation which describes generic flat-band models, we propose a systematic way to construct a class of flat-band models with finite-range hoppings that have topological natures. In these models, the topological natures are encoded not into the flat band itself but into the dispersive bands touched with the flat band. Such a band structure may become a source of exotic phenomena arising from the combination of flat bands, topology and correlations.