Europhysics Letters (EPL)
Quasi-Particle Amplitudes in the 1- and 2-Dimensional t - J Model
Jin‐Oh Song, James F. Annett
Abstract
Using the t - J model of high- T c superconductors, we calculate the exact one-hole quasi-particle energies, E ( k ), and weights, Z ( k ), for clusters of up to 20 sites in size. We find that in all 2-dimensional clusters Z is relatively large (0.2 ÷ 0.4) at the Fermi energy, E F , and is a maximum there. These results are not consistent with the marginal or Luttinger Fermi liquid theories of high- t c superconductivity. Extrapolating to the thermodynamic limit is not possible with square lattices, however, we do find Z → 0 in N × 1 chains, as expected in a Luttinger liquid, and Z → constant in N × 2 chains implying a Landau Fermi liquid.