Tuesday 25 March 2025
Fractional Chern insulators – from theory to realization in moire materials
Cécile Repellin (CNRS Grenoble)

Fractional Chern insulators (FCIs) are the lattice equivalent of the fractional quantum Hall effect, whereby the intrinsic properties of the lattice provide the necessary ingredients for the emergence of this strongly correlated phase. Their existence was first demonstrated numerically in toy models, where turning on strong local interactions in Chern bands resulted in a FCI ground state. During this Flat Club seminar, I will give an informal overview of the theory of FCIs and their stability in microscopic models, and discuss their recent experimental observation in twisted bilayer MoTe2, and in rhomboedral multilayer graphene. We will end with a discussion of open questions in the field of FCIs.