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A Study of the S=1/2 Alternating Chain using Multiprecision Methods

T. Barnes·J. Riera·D. A. Tennant
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Abstract

In this paper we present results for the ground state and low-lying excitations of the $S=1/2$ 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.

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T. Barnes, J. Riera, D. A. Tennant. 1998-01-21. A Study of the S=1/2 Alternating Chain using Multiprecision Methods. https://doi.org/10.1103/physrevb.59.11384

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