QUASI-PARTICLE DISPERSION IN THE CUPRATE SUPERCONDUCTORS AND THE 2-DIMENSIONAL HUBBARD-MODEL

The momentum dispersion of the peak structure of the single-particle spectral weight A (p, omega) of the two-dimensional Hubbard model is discussed. Using results obtained from Monte Carlo simulations on lattices up to 12 x 12 in size, we determine the low-lying quasiparticle dispersion relation. This dispersion relation is anomalously flat near the (pi,0) and (0,pi) points of the Brillouin zone, similar to the results of recent angular resolved photoemission measurements of the hole-doped cuprates. We argue that the generic nature of the quasiparticle dispersion relation observed in these materials arises from the strong Coulomb interaction and reflects the hole-spin correlations rather than the one-electron interactions which customarily determine the band structure.