Key points are not available for this paper at this time.
Neutron scattering has shown that the lowest spin excitations in the spin-1 antiferromagnet CsNiCl₃ in its one-dimensional phase occur at finite frequency. After allowance for the known weak interchain coupling the gap is found to be in good agreement with recent numerical calculations. The results support the Haldane conjecture that in integral-spin chains with isotropic interactions a gap separates the ground state from the excitations.
Buyers et al. (Mon,) studied this question.