Fractional Chern Insulators beyond Laughlin states

Understand

We report the first numerical observation of composite fermion (CF) states in fractional Chern insulators (FCI) using exact diagonalization.

• The ruby lattice Chern insulator model for both fermions and bosons exhibits a clear signature of CF states at filling factors 2/5 and 3/7 (2/3 and 3/4 for bosons).
• The topological properties of these states are studied through several approaches.
• Quasihole and quasielectron excitations in FCI display similar features as their fractional quantum hall (FQH) counterparts.