Haldane-Gapped Spin Chains as Luttinger Liquids: Correlation Functions at Finite Field
Abstract
We study the behavior of Heisenberg, antiferromagnetic, integer-spin chains in the presence of a magnetic field exceeding the attendant spin gap. For temperatures much smaller than the gap, the spin chains exhibit Luttinger liquid behavior. We compute exactly both the corresponding Luttinger parameter and the Fermi velocity as a function of magnetic field. This enables the computation of a number of correlators from which we derive the spin conductance, the expected form of the dynamic structure factor relevant to inelastic neutron scattering experiments, and NMR relaxation rates. We also comment upon the robustness of the magnetically induced gapless phase both to finite temperature and finite couplings between neighbouring chains.
Keywords
Cite
@article{arxiv.cond-mat/0106037,
title = {Haldane-Gapped Spin Chains as Luttinger Liquids: Correlation Functions at Finite Field},
author = {Robert M. Konik and Paul Fendley},
journal= {arXiv preprint arXiv:cond-mat/0106037},
year = {2009}
}
Comments
32 pages, 8 figures; published version includes additions discussing the robustness of the magnetically induced gapless phase to ordering between chains as well as the relationship between the spin-1 chains and spin-1/2 ladders in the presence of a magnetic field