CORRELATION-FUNCTIONS AND DYNAMIC PROPERTIES OF THE ONE-DIMENSIONAL HUBBARD-MODEL

The oscillating behaviors of correlation functions in real space are determined for the one-dimensional Hubbard model with various electron densities and arbitrary values of U by the exact-diagonalization technique. Of them, the oscillation of density-density correlation function depends drastically on the value of U and doping: The oscillation occurs at 2k(F) for small U or large doping and at 4k(F) for large U or small doping. The pairing susceptibility in the singlet channel shows 2k(F) oscillations while there are no oscillations in the triplet channel. The hole spectral function is also calculated, and it is found that in the large-U limit the dynamical property of a single hole depends strongly on the background with doping.