Title: Light-induced band-topology & metal-insulator transitions in interacting Kagome lattice

Abstract:

We study the interplay between electron interaction and external periodic circularly-polarised light drive on Kagome lattice in the off-resonant limit. Employing the Brillouin-Wigner perturbation theory we derive an effective Hamiltonian and show that in the non-interacting limit the periodic drive not only modulates the bare hopping amplitudes but generates new hopping terms that bestow non-trivial topology to the bands. We then employ slave-rotor mean field theory to investigate correlation effects in the system at half-filling and demonstrate repeated metal to topological-Mott-insulator phase transitions with the light amplitude at intermediate interaction strengths. At strong interaction strengths, we find periodic topological phase transitions between insulating states with distinct band topologies. We show that due to the interplay of emergent chiral hopping spinon flat bands are generated in the Mott insulating phase. We briefly discuss ways to realize the model in cold-atomic systems. Finally from the interacting model study, we propose an electronic-chiral Hamiltonian which has a rich topological band structure where electronic-flat bands can be engineered.