Strongly interacting Luttinger liquid - exact solution of a generalized t-J model in one dimension

Luttinger liquids are characterized by the critical exponent Theta of the m omentum distribution around the Fermi momentum k(F). Typically Theta less t han or equal to 1/2, signalling a singularity characterizing a residual Fer mi surface. Results of photoemission experiments can be interpreted in term s strongly interacting Luttinger liquids with Theta greater than or equal t o 1 with the residual Fermi surface disappearing. We construct integrable m odels with such behaviour-models given by the SU(nu) t-J interaction with a hard-core repulsive potential between electrons at distances less than or equal to Delta. The models exhibit both weakly and strongly interacting Lut tinger behaviours with Theta varying continuously in the range 0 less than or equal to Theta less than or equal to 1/2 (1 + Delta - 1/[nu (1 + Delta)] )(2) depending on the electron density. In the extreme high-density limit t he model exhibits a Mott-Hubbard gap and reduces to an isotropic Heisenberg chain with a new spacing parameter Delta + 1.