1/N EXPANSION FOR THE SCHWINGER-BOSON THEORY OF QUANTUM ANTIFERROMAGNETS

We investigate static properties of the two-dimensional quantum Heisenberg antiferromagnet in the framework of the 1/N expansion of the CPN-1 model. The calculations are done in the renormalized-classical region. The logarithmic corrections to the spin-correlation length are found to change the temperature dependence of its prefactor. The renormalized staggered susceptibility is completely determined by the renormalization of the spin-correlation length. The results we obtain are in agreement with the renormalization-group and 1/N studies of the O(N) nonlinear σ model. © 1994 The American Physical Society.