SPIN-WAVE THEORY AND FINITE-SIZE SCALING FOR THE HEISENBERG-ANTIFERROMAGNET

Spin-wave perturbation theory for the Heisenberg antiferromagnet at zero temperature is used to compute the finite-lattice corrections to the ground-state energy, the staggered magnetization, and the energy gap. The dispersion relation, the spin-wave velocity, and the bulk ground-state energy to order O(1/S2) are also computed for the square lattice. The results agree very well with the predictions of Neuberger and Ziman and the predictions of Fisher.