Projected spin wave theory. II. Ground state properties of S=1/2 Heisenberg antiferromagnets

Abstract

For pt.I see ibid., vol.18, p.6247 (1985). The ground state properties of the S=1/2 antiferromagnetic Heisenberg Hamiltonian are analysed in the light of the projected spin wave theory previously reported, which takes into account the kinematical interaction (KI). It is shown that the inconsistency found for the zero point energy as obtained from different boson mappings is due to the fact that in the usual spin wave theory the KI is either neglected or not considered. Moreover, values of zero point spin reduction and zero energy shift are calculated with increasing accuracy and compared with the ground state estimates reported in the literature. The validity of the assumptions for the antiferromagnetic ground state is discussed and found to become worse as the lattice dimensionality becomes lower.