Quantum Monte Carlo study of spin correlations in the one-dimensional Hubbard model

The one-dimensional Hubbard model is studied at and close to half-filling using a generalization of Handscomb’s quantum Monte Carlo method. Results for spin-correlation functions and susceptibilities are presented for systems of up to 128 sites. The spin-correlation function at low temperature is well described by a recently introduced formula relating the correlation function of a finite periodic system to the corresponding T=0 correlation function of the infinite system. For the T→0 divergence of the q=2k_F spin susceptibility, our results are consistent with the form χ(2k_F)∼‖ln(T)‖^σT_ρ^K-1, with σ=1/2.