ONE-DIMENSIONAL T-J MODEL WITH NEXT-NEAREST-NEIGHBOR HOPPING - BREAKDOWN OF THE LUTTINGER LIQUID

We investigate the effect of a next-nearest-neighbor hopping integral t' in the one-dimensional t-J model, using Lanczos diagonalization of finite chains. Even moderate values of t' have a dramatic effect on th e dynamical correlation functions and Fermi-surface topology. The high -energy holon bands become diffuse and overdamped, and the band struct ure near the Fermi energy is dominated by t'. With increasing hole con centration the system undergoes a phase transition that changes the vo lume of the Fermi surface, but neither phase has a k(F) compatible wit h a Luttinger liquid.