Quantum Phase Diagram Of The One-Dimensional Deformed T-J Model

In this work, we use bosonization field theory and renormalization group calculation to investigate the phase diagram of a deformed one-dimensional t-J model of correlated electrons with anisotropic antiferromagnetic exchange at half-filling.The deformed t-J model is characterized by replacing the fermion operators c_j,α of hopping term with deformation Hubbard operators c_j,α= c_j,α(1- λ_j,-α)（0 < λ 1） in the weak-coupling regime, for anisotropic antiferromagnetic exchange terms remaining unchanged. For 0 < λ 1, there is a nonzero probability to allow leakage into states with double occupancy, In case the double occupation is allowed, the on-site U should be considered and the deformation parameter λ softens the induced two-and three-body interaction strengths, and all the induced interactions can be treated as perturbations and an effective field-theoretical approach may be safely used.The properties of the t- J_⊥- J_z model are determined by the critical value λ_c=√（（πU）/8）. When λ > λ_c, the ground state consists of the triplet-superconducting（TS） correlations and insulating spin-density-wave（SDW） and bond-charge-density-wave（BOW）phases. When λ ≤ λ_c, the anisotropy（J_⊥≠J_z） leads to the removal of critical spin correlations and the charge gap is opened everywhere, then the superconductivity（SC）correlations is disappeared, and the insulating phases is kept. The result indicates that the physics of the deformed version is not equivalent to that of the conventional t-J model.