The renormalization-group analysis of the ground state of the spin-antiferromagnetic chain

We are interested in the anisotropic spin-1 antiferromagnetic chain. System of particles with an arbitrary «large» spin is described directly from the first principles, based on the symmetry law. The ground state of the one-dimensional s = 1 pseudo-Heisenberg antiferromagnet with single-ion anisotropy is calculated using the renor-malization group analysis. Excitations of the chain in the form of linear spin waves are considered. The excitation spectrum has a gap.