Abstract
We discuss the metal-insulator transition of the spinless fermion model on a kagome lattice at filling. The system is analyzed by using exact diagonalization, density-matrix renormalization group methods, and random-phase approximation. In the strong-coupling region, the charge-ordered ground state is consistent with the predictions of an effective model, i.e., plaquette order. We find that the qualitative properties of the metal-insulator transition are totally different depending on the sign of the hopping matrix elements, reflecting the difference in the band structure near the Fermi level.
- Received 5 January 2010
DOI:https://doi.org/10.1103/PhysRevLett.104.196401
©2010 American Physical Society