Journal of Physics Condensed Matter
Strongly interacting Luttinger liquid - exact solution of a generalizedt-Jmodel in one dimension
Igor N. Karnaukhov, Natan Andrei
Abstract
Luttinger liquids are characterized by the critical exponent Θ of the momentum distribution around the Fermi momentum k F . Typically Θ⩽1/2, signalling a singularity characterizing a residual Fermi surface. Results of photoemission experiments can be interpreted in terms strongly interacting Luttinger liquids with Θ⩾1 with the residual Fermi surface disappearing. We construct integrable models with such behaviour - models given by the SU(ν) t - J interaction with a hard-core repulsive potential between electrons at distances less than or equal to Δ. The models exhibit both weakly and strongly interacting Luttinger behaviours with Θ varying continuously in the range 0⩽Θ⩽½(1 + Δ-1/[ν(1 + Δ)]) 2 depending on the electron density. In the extreme high-density limit the model exhibits a Mott-Hubbard gap and reduces to an isotropic Heisenberg chain with a new spacing parameter Δ + 1.