MONTE-CARLO METHOD FOR OBTAINING THE GROUND-STATE PROPERTIES OF QUANTUM SPIN SYSTEMS

Monte Carlo method to find the ground-state properties of quantum spin systems is presented. Transforming a quantum spin Hamiltonian in a ma trix with non-negative elements, we et up a Markov process whose stati onary probability is dominated by the leading eigenvector of this matr ix. From the simulation of the Markov process, by means of a Metropoli s algorithm, we obtain the properties and the energy of the ground sta te. The method is applied to the spin-1 isotropic, Heisenberg antiferr omagnet chain.