Correlations in the ground state of the one-dimensional Hubbard model

N. M. Bogoliubov, V. E. Korepin

Masatoshi Imada, Nobuo Furukawa, Thomas Maurice Rice

The crossover of the spin correlation function from a non-half-filled to a half-filled band is investigated for the one-dimensional Hubbard model in the ground state. For the on-site interaction U →∞ , it has the form at distance r ,

A. M. Finkel'Shteǐn

Romuald L yżwa, Zbigniew Domański

Ground-state properties of the asymmetric Hubbard model are studied on one-dimensional clusters (rings) with N=6, 8, and 10 sites. The ground-state energy, correlation functions, and phase diagrams are determined for various sets of model parameters. Computations are performed both by exact diagonalization (for N=6) and by an approximate method by which correlation effects can be examined on larger clusters than exact diagonalization allows. In the limiting cases (one limit corresponds to the spinless Falicov-Kimball model and the other to the Hubbard model) our results agree quite well with those obtained analytically for infinite systems.

Liang Chen, Changjiang Mei

The single-band Hubbard model has been studied in both the one-dimensional ring and two-dimensional torus. By the exact calculation of the pair correlation function F(i,j), defined as the possibility of finding an electron at site j when there has been an electron at site i, it is shown that for two electrons, the interaction is always repulsive in the ground state for any positive value of the on-site Coulomb interaction U.

MANFRED L. RISTIG