%0 Journal Article
%T Dynamical Properties of a Haldane Gap Antiferromagnet
%A O. Golinelli
%A Th. Jolicoeur
%A R. Lacaze
%J Physics
%D 1992
%I arXiv
%R 10.1088/0953-8984/5/9/024
%X We study the dynamic spin correlation function of a spin one antiferromagnetic chain with easy-plane single-ion anisotropy. We use exact diagonalization by the Lancz\H os method for chains of lengths up to N=16 spins. We show that a single-mode approximation is an excellent description of the dynamical properties. A variational calculation allows us to clarify the nature of the excitations. The existence of a two-particle continuum near zero wavevector is clearly seen both in finite-size effects and in the dynamical structure factor. The recent neutron scattering experiments on the quasi-one-dimensional antiferromagnet NENP are fully explained by our results.
%U http://arxiv.org/abs/cond-mat/9212014v1