Commensurate–incommensurate transition in a one-dimensional dimerized electron system close to quarter-filling

We investigate electronic states upon doping (i.e., by varying the chemical potential) for a quarter-filled one-dimensional electron system with a dimerization, on-site and nearest-neighbor repulsive interaction. By applying the renormalization group method to the bosonized Hamiltonian, the metal–insulator transition followed by commensurate–incommensurate transition is obtained for Mott insulating region as well as charge ordered insulating regime. We discuss the phase diagram on the plane of the chemical potential and the interaction.