GROUND-STATE PROPERTIES OF THE SPIN-1/2 ANTIFERROMAGNETIC HEISENBERG MODEL ON A CUBIC LATTICE BY A MONTE CARLO METHOD

The spin-1/2 antiferromagnetic Heisenberg model with spatial anisotropy is studied on a cubic lattice by a Monte Carlo Method. Two types of spatial anisotropies are considered: planar and axial. The staggered magnetization m† and the ground state energy per site ∊0 are obtained as a function of the anisotropy. In the isotropic case we have obtained m† = 0.429 ± 0.001 in units where the saturated value is 0.5 and ∊0 = –0.899 ± 0.001.