Frustration-driven singlet superconductivity in the one-dimensional t−U−J1−J2 model with positive interactions

Motivated by the discovery of iron-based superconductors, we analytically investigate the one-dimensional correlated electron system described by the t−U−J1−J2 model at weak coupling and at half filling. The low-energy field theory analysis combining the bosonization and renormalization-group scenario helps us to derive the quantum phase diagram, which includes a spin density wave phase, a bond order wave phase and a superconducting phase characterized by the coexistence of singlet superconductivity and charge density wave instabilities. The frustration J2 accounts for the realization of the superconductivity in the regime of positive interactions.