Charge- and spin-susceptibilities in the one-dimensional hubbard model with long-range interaction

Abstract

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 2 k F and 4 k 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 α in the spectral function ϱ( ω) ∼ | ω| α 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.