Coexisting orders in the quarter-filled Hubbard chain with elastic deformations

The electronic properties of the quarter-filled extended Peierls-Holstein-Hubbard model that includes lattice distortions and molecular deformations are investigated theoretically using the bosonization approach. We predict the existence of a wide variety of charge-elastic phases depending of the values of the Peierls and Holstein couplings. We also study perturbatively the effects of the Peierls deformation in the nearest-neighbor repulsion V, that may be present in real materials where Coulomb interactions depend strongly on the distance. Our results indicate that the phase diagram may change substantially with V when this term is taken into account.