Fractional Chern insulators on hyperbolic lattices with singularity
Phys. Rev. B 112, 115114 – Published 5 September, 2025
DOI: https://doi.org/10.1103/gf6q-kxh3
Abstract
Fractional Chern insulators (FCIs), as a platform for the realization of fractionalization phenomena without external magnetic field, have attracted great interest. To realize FCIs, topological flat bands play a significant role. Most recently, FCIs have been extended into two-dimensional hyperbolic systems and the geometric degree of freedom of hyperbolic FCIs has been revealed. In this work, we construct hyperbolic lattices with a conical singularity and demonstrate the existence of topological flat bands. Subsequently, a bosonic FCI state is investigated on these hyperbolic topological flat band models with a singularity. The edge excitations for these singular hyperbolic FCIs are investigated. We also construct the optimal trial wave functions for the FCI state and roughly explore the interplay between the FCI state and geometric factors originated from the hyperbolic geometry and conical singularity.