Department Colloquium | Flat Bands, Topology, and Fractionalization - A New Pathway Towards Fractional Topological States

In this talk, I will first provide a review about various flat band systems and the nontrivial physics that emerges from these flat bands and heavy electrons, with main focus on fractional topological states and fractional excitations. In contrast to the conventional approach, such as the fractional quantum Hall effect, which requires a strong external magnetic field, here we explore a new pathway towards the same type of exotic fractional particles through spontaneous symmetry breaking with zero external magnetic fields. We show that utilizing realistic material parameters and the method of exact diagonalization, these fractional states can be stabilized in Moiré superlattices of transition metal dichalcogenides (TMD).