arXiv:cond-mat/0312055 · Physical Review B
Itinerancy effects on spin correlations in one-dimensional Mott insulators
M. J. Bhaseen, Fabian H. L. Eßler, Anja Grage
Abstract
We consider spin correlations in the one-dimensional (1D) half-filled repulsive Hubbard model. For very large values of the on-site repulsion $U$ the spin correlations are dominated by virtual hopping processes of electrons and are described in terms of a spin-$1∕2$ Heisenberg chain. As $U$ is decreased real hopping processes of electrons become important and eventually dominate the spin response. We discuss the evolution of the dynamical structure factor as a function of $U$. We comment on the relevance of our results for inelastic neutron-scattering experiments on quasi-1D materials.