- Editors' Suggestion
Composite Fermion Theory of Fractional Chern Insulator Stability
Phys. Rev. Lett. 136, 066504 – Published 13 February, 2026
DOI: https://doi.org/10.1103/shrz-b692
Abstract
We develop a mean-field theory of the stability of fractional Chern insulators based on the dipole picture of composite fermions (CFs). We construct CFs by binding vortices to Bloch electrons and derive a CF single-particle Hamiltonian that describes a Hofstadter problem in the enlarged CF Hilbert space, with the trace-condition term emerging naturally in the small- limit as part of the CF Hamiltonian. Going beyond the small- limit, we apply our theory to twisted and calculate its CF band structures. The resulting CF phase diagram matches closely with that from exact diagonalization, and the projected many-body wave functions achieve exceptionally high overlaps with the latter. Our theory provides both a microscopic understanding and a computationally efficient tool for identifying fractional Chern insulators.