Doping dependence of the phase diagram in one-dimensional extended Hubbard model: a functional renormalization group study.

Using functional renormalization group method, we studied the phase diagram of the one-dimensional extended Hubbard model at different dopings. At half filling, variety of states strongly compete with each other. These states include spin-density wave, charge-density wave, s-wave and p -wave superconductivity, phase separation, and an exotic bond-order wave. By doping, system favours superconductivity more than density waves. At 1/8 doping, a new area of extended s-wave superconductivity emerges between charge density wave and bond-order wave regions. If the system is doped to 1/4-doping, a new area of p -wave superconductivity emerges between charge-density wave and spin-density wave regions.