W. Lu et al., HALDANE-GAP RELATED ENERGY-STATES IN SPIN S = 1 LINEAR-CHAIN HEISENBERG-ANTIFERROMAGNET, Chinese Physics Letters, 11(3), 1994, pp. 177-180
Some fundamental properties are found for the singlet ground state and
lowest triplet excited state in the spin s = 1 linear chain Heisenber
g antiferromagnet with arbitrary chain length. The influence of the an
isotropic term on these states is evaluated by spin polarization on th
e site of the chain. The energy levels based on these analyses are in
good agreement with the experimental spectroscopes.