Lattice-Induced Splitting, Connectivity, and Topology of Anyon Bands

Abstract

Fractional Chern insulators realize fractional quantum Hall states without external magnetic fields, while their underlying lattice periodicity allows otherwise dispersionless anyons to acquire finite bandwidth. Here we show that flux--lattice commensurability can also give rise to multiple anyon bands with nontrivial topology and symmetry-protected connectivity. In multiband vortexable systems, commensurability between the lattice periodicity and the effective magnetic unit cell of fractionally charged quasiholes leads to the folding of a quasihole Landau level into multiple bands. Interactions lift their degeneracy, producing dispersive bands with Chern numbers distinct from that of the parent quasihole Landau level. We further demonstrate that these Chern numbers can be redistributed through Dirac crossings under continuous deformations that preserve exact electronic flatness, while crystalline symmetries can enforce protected band touchings. Our results establish that fractionalized excitations can exhibit the rich band topology familiar from electronic Bloch bands, opening possibilities for nontrivial anyon dynamics beyond conventional Landau-level physics.