Fractional Chern insulators arise in topologically nontrivial flat bands, characterized by an integer Chern number $\mathit{C}$ that corresponds to the number of dissipationless edge states in the noninteracting regime. Higher Chern numbers can replicate the physics of higher Landau levels and often confer enhanced topological robustness. However, realizing correlated fractional phases with higher Chern numbers in such flat band systems remains challenging. Here, we propose an interlayer coupling scheme to generate higher Chern numbers in a flat-band system, where the interlayer coupling transforms two $\mathit{C}=\text{1}$ bands in a bilayer checkerboard lattice into a single flat band with $\mathit{C}=\text{2}$ by lifting their degeneracy and merging their topological indices. Exact diagonalization calculations reveal that this engineered band hosts two fractional Chern insulator states with many-body Chern numbers $\mathit{C}=2/3$ and 2/5 at fillings of $\nu =1/3$ and 1/5, respectively. An experimental setup is proposed to simulate these states using cold alkaline-earth-like atoms in an effective bilayer optical lattice. Our work provides a general and widely applicable strategy for constructing higher Chern number flat bands, opening a pathway to explore exotic fractional quantum phases.

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• Flat bands
• Landau levels
• 2-dimensional systems
• Topological materials
• Electric moment
• Exact solutions for many-body systems
• Tight-binding model