A Study of the S=1/2 Alternating Chain using Multiprecision Methods
Abstract
In this paper we present results for the ground state and low-lying excitations of the alternating Heisenberg antiferromagnetic chain. Our more conventional techniques include perturbation theory about the dimer limit and numerical diagonalization of systems of up to 28 spins. A novel application of multiple precision numerical diagonalization allows us to determine analytical perturbation series to high order; the results found using this approach include ninth-order perturbation series for the ground state energy and one magnon gap, which were previously known only to third order. We also give the fifth-order dispersion relation and third-order exclusive neutron scattering structure factor for one-magnon modes and numerical and analytical binding energies of S=0 and S=1 two-magnon bound states.
Cite
@article{arxiv.cond-mat/9801224,
title = {A Study of the S=1/2 Alternating Chain using Multiprecision Methods},
author = {T. Barnes and J. Riera and D. A. Tennant},
journal= {arXiv preprint arXiv:cond-mat/9801224},
year = {2009}
}
Comments
16 pages, 9 figures. for submission to Phys.Rev.B. PICT files of figs available at http://csep2.phy.ornl.gov/theory_group/people/barnes/barnes.html