We discuss the properties of spin-wave theory of quantum antiferromagnets with an additional constraint that restores the sublattice symmetry. Our treatment is analogous to Takahashi’s recent theory of low-dimensional ferromagnets, and closely related to the Schwinger boson theory of Arovas and Auerbach. We obtain exact results for spin-spin correlations of 2, 4, and 8 spins in a singlet state, and exceedingly close agreement with exact results for S=(1/2 in a variety of other cases. The implication for the long-range order of the d=2, S=(1/2 Heisenberg antiferromagnet is discussed.

• Received 6 January 1989

DOI:https://doi.org/10.1103/PhysRevB.40.4769