ZERO-TEMPERATURE PHASE-DIAGRAM OF THE ONE-DIMENSIONAL T-J MODEL

We study the t-J model in one dimension by combining a variational app roach and an exact ground-state projection method. We find that the mo del exhibits Luttinger-liquid behavior for most of the phase diagram b efore the critical J/t for phase separation. However, at small densiti es and high interaction strengths, a new Luther-Emery-liquid phase wit h a gap to spin excitations and enhanced superconducting correlations is found.