CHARGE-SUSCEPTIBILITIES AND SPIN-SUSCEPTIBILITIES IN THE ONE-DIMENSIONAL HUBBARD-MODEL WITH LONG-RANGE INTERACTION

Effects of long-range Coulomb interaction in one-dimensional electron systems are studied. By using a quantum Monte Carlo method, we obtain that the zero-frequency wave-number dependent charge susceptibility at quarter-filling shows both 2k(F) and 4k(F) singularities, k(F) being the Fermi wave number, in contrast with the Hubbard model with the on-site and nearest-neighbor interactions. The results are in accord with the X-ray experiments in (NMP)(x)(Phen)(1-x)(TCNQ). The power-law exponent alpha in the spectral function rho(omega) similar to \omega\(alpha) observed in the high-resolution photoemission experiments is calculated by using the exact diagonalization method and found to increase with increasing the range of the interaction.