Itineracy Effects on Spin Correlations in 1D Mott Insulators

TL;DR

This paper investigates how spin correlations in 1D Mott insulators evolve with the on-site repulsion U, transitioning from a Heisenberg chain description to real electron hopping effects, relevant for neutron scattering experiments.

Contribution

It provides a detailed analysis of the evolution of spin correlations in the 1D Hubbard model as U varies, linking theoretical predictions to experimental observations.

Findings

Spin correlations dominated by virtual hopping at large U

Real hopping processes become significant as U decreases

Results are relevant for interpreting neutron scattering data

Abstract

We consider spin correlations in the one dimensional 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.